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Mazda Millenia EGR problem

kaczjoneskaczjones Member Posts: 1
I have had an EGR problem with my 1999 Mazda Millennia since the first week a I had purchased it in 2002. They replaced the EGR valve and knock sensor multiple times. They even drilled bigger holes in the engine and my engine light continues to remain on. Now the engine light is blinking. Any suggestions? The dealership where I have been taking it to told me to ignore the light. The only thing is $3000.00 later I have the same problem but now can not drive it because the light is blinking. The dealership told me now I have to replace a part that is going to cost around 2600.00 just for the part. Please help with any advise!!! I can not trade it in or drive it!


  • patpat Member Posts: 10,421
    You might also want to post this in our Technical Questions discussion. It's not limited to the Millenia and I think you'll find more gearheads hanging out there than you will here.

    But we'll wait to see if someone here can help as well.

    Good luck.
  • easylivingeasyliving Member Posts: 4
    Does anyone have the layout for the oxygen sensors for the 99 mm S. I need to find the bank 2 oxygen sensor.

    Thanks for your help
  • lovemykidslovemykids Member Posts: 1
    I really don't have any suggesstions other than write a letter to the main boss of Mazda. Its rediculous that you can not trade or drive the car. A part that small should not cost so much. I would expect that price on a major part (engine, Tranny...) I am having similar problems with my 2001. I can not seem to get the check engine light to stay off. I have replaced the EGR Valve, put fuel system cleaner in it and cleaned out the ports. I had a mechanic look through the whole emissions system and he says everything is working as it should, but the light continues to come on. I am sorry for your bad luck with the car. It seems many owners are haveing similar problems. You would think Mazda would do a recall, but you know they are in it for the money.
  • jennifertnjennifertn Member Posts: 1
    I have had this problem for 3 years, the only way i past emition last yearr was because a friend new a friend that passed me. Dont know what im going to do this year. Mazda cant fix the problem
  • jazzyman26jazzyman26 Member Posts: 18
    I'm having the same issue with the CEL light 01 2.5 for the pass year didn't pass emission was able to get trough it in 06.Replace two sets of converter o2 sensor EGR valve clean smoke test perform still CEL light on.Back and forth to the shop original converter was tested and fuctional TSB on the o2 sensor.Can't drive the due to expire tag I had 2 temporary tag can't receive anymore,notified the Dept of Safety in Tenn about this situation to request a hardship so I can bypass emission to drive the back and forth to work
    and have more test perform. and possible an EPA issue.
    The last diagnostic code P0431 if anyone can help does this code mean I need a converter or pre cat? and what web site I can find a pre -cat and price.I don't want to trade the car looking to move into another house don't want another bill.If this continue I might not have any choice but to trade.I went to three independent dealer and was told to replace the cat converter,but the mazda dealer stated that I need pre-cat talk about confusion.Need help
  • jazzyman26jazzyman26 Member Posts: 18
    1. Replace both 02 sensor code reset.
    2. P0420 code cat convertor
    3.Replace fron and middle converter code reset
    4.P0431 code appears again
    5.replace both cat convertor CEL still on
    6.TSB on both 02 sensor
    7.02 sensor replace CEL still on
    8. Pass emission in 06
    9.Diagnostic perform from 3 other dealer Cat code
    10.Tenn Dept of Safety State emission analyzer code P0431
    11. Mazda Dealer might need pre-cat due to Codes P0431
    12.EGR Valve clean
  • chozenchozen Member Posts: 1
    I have had a 1999 and a 2000 Millenia. The EGR value issue is a big chaotic problem, yet with a simple solution. If you take the intake off the throttle body, and remove the four screws that hold the throttle body on and remove it also. You WILL see a really clogged hole in the bottom. If you take some engine cleaner, and spray it in it will break up the build up. I usually straighten a paperclip and clear the hole that way, but I think it would be better to instead of letting it fall through, picking it out. The check engine light will stay off, until there's another buildup. It is hardly ever the EGR Valve. Only few mechanics know this, so when they replace the EGR and it still does the same, you are all confuse. Wierd enough, you may also have carbon deposits in your exhaust, please don't check it while it's running. LOL
  • megaquarkmegaquark Member Posts: 2
    Had the same problem a few years ago. There is a EGR sensor (or something like that) that is up in the middle slightly to the passenger side right up by the firewall. It plugs into a harness. It has a Mitsubishi emblem on it. Take it out. Start the car. Always have the TCF off light on and the engine light, but no more stalling. :-)

    (note, this is a completely different problem from the previous one I just posted- I felt that if I was asking, I might give something back)

    Apparently this car has a history of a faulty computer that turns the TCS off light on when it shouldn't. So the TCS off light is misleading. It has nothing to do with the TCS - it's emissions. Removing the sensor has solved the problem on 4 others that I know of. Happy driving!
  • tommyquatommyqua Member Posts: 10
    same problem here 99 Millennia S.
    have been driving with the Check Eng Light on for almost a year. Recently it started to blink. took it in to Firestone for Diag; they told me i have PO-431 Ignition coil #4 mised fire and typical O2 sensor issue. I plan to chang my spark plug this weekend. Don't spend money on O2 and anything more than a Thousand dollars repair just ignord it as long you have AAA just drive this car and have a good time - I really like this car but have no intention to upkeep it,
    cars are losing proporsition from day one.
    just gas and zoom.
  • tommyquatommyqua Member Posts: 10
    PO-431 mean mised fire - replace the ignition coil.
    go to Pepboys they sell it for $149, $90 installation.
    replace the spark plug yourself but i think you can only
    buy the distributor cap from the dealers.
    Diag at Firestone is about $59 but i believe you can get a free one from PeppBoys.
  • goodcargoodcar Member Posts: 4
    Duh!! In it for the money? Do you really think so?
  • jazzyman26jazzyman26 Member Posts: 18
    If anyone and a Mechanic can give me some insight pre-cats (both front) 2.5l 01
    I"m considering buying two universal catalyic converter instead of going to the dealer paying $ 2000.00 can this be done or do I have to go to the dealer?If anyone
    that have the same issue and use universal catalyic let me know please before I spend the money and what brand is best for universal converter Eastern or Magnflow
  • gnc54gnc54 Member Posts: 1
    hey i have an 02 mazda millenia with an EGR VALV and CAT CONVERTER prob how do i fix that? how much is it to fix? does it make sence to even fix it?
  • hawaiianmikehawaiianmike Member Posts: 13
    If you have determined that the EGR system is actually OK, then try the following:
    1) Replace air filter--K&N hi-perf filter runs about $65 and is worth it-

    2) double check battery posts/connections---clean/replace as necessary-

    NO check engine light should BLINK and that may indicate a screwed up computer---very expensive!! Last resort-

    Since you have the supercharged model, it's possible that you have too much boost---as nice as it is, the boost just uses up more gas and, let's be realistic here, it's not going to walk away from a BMW M3 or Porsche, so turn the boost down and see if that clears the indicator----you know that you can turn the light off by simply disconnecting the battery, right? (have to reset all your stereo channels--bummer) BUT IF YOU CLEAN UP THE BATTERY POSTS WHILE YOUR AT IT, IT'S WORTH THE EFFORT--

    code reader may be also worth the $300----good luck and aloha, Mike in Kaneohe
  • angelmazdaangelmazda Member Posts: 6
    i was told by auto zone that these diagnostic codes needed to be addressed:
    p0301 & p0170 & p1522

    i have already changed the cyl#1 spark plug(to fix #p0301)
    i had the mechanic do an injector cleaning
    i closed the screw on the idle and it would not adjust, it remains @ 800 rpm
    Can someone plz help me and give me an idea as to what i have to do for these problems. Hopefully someone knowledable can assist.
  • hawaiianmikehawaiianmike Member Posts: 13
    Dude---do yourself a favor and do it once & do it right---replace all 6 spark plugs AND the wires---I realize that this can run some bucks but you will thank yourself (and maybe me too!!) when your Mazda runs at near 100% and you also get maybe 5 miles per gallon better mileage---I have done it twice (2 different cars) and the diff was incredible----runs better, more pull and better gas mileage, and better reliability thrown in as a gift--I had to replace my distributor ($500 my friend!) but it was THE SOLUTION to my problem at the time---I have a used one that is OK which I would sell for $100 if you need one-- ( I am assuming that you do NOT HAVE a supercharged, Miller-cycle engine as I am NOT familiar with that option!!)--I run 89 octane gas, and am forced by Hawaii law to use 10% METH gas, and usually add a bottle of gas treatment when at 1/2 tank---I am getting around 22-24 MPG on average, so it's a decent rate--you gotta watch your mileage as it is not just about dollars, your mileage also reflects the overall status of your motor----keep your oil clean (change oil & filter every 5K mi or so, and always check the condition of your hoses every 4-6 months)---especially the emissions-related (like CGR and others) that can result in a motor that is not only polluting the air but running HOT---(a bad thing here in Hawaii!!)--these cars are very solid and can run over 200K easily IF YOU MAINTAIN THEM!!!--I have an entire 1995 motor laying in my driveway, next to the tranny and all sorts of accessory parts (starter, alt., A/C compressor, and on and on) + wheels, tires and more----it's a very good model to stay with long term---one tip I'll give you is to break down a good sized cardboard box and slide it under the car, motor area above, and right after returning from a trip so everything is hot, and look for any fluid leaks----the Millenia is known for leaks from the rack & pinion steering (up against firewall), and also the valve covers--(front one duck soup, rear one a real pain), and anything else that may show up----discovering the leak source(s) can save you a lot of $$$$$ not to mention a possible tow job----watch battery water level and tape a penny onto the battery near the posts---it will stop the battery from crapping out the electrolyte---trust me, just do it!!! Also, don't forget that the tires are UNIDIRECTIONAL, so you can put driver front to driver rear, and the reverse, but DON'T put left side tires onto right side (passenger side) unless you have $300 to blow----

    You are welcome to get me at [email protected] rather than the forum---either way!!!

    Aloha, Mike
  • angelmazdaangelmazda Member Posts: 6
    The email address "" is not recognized. Please fix it and try again.
  • angelmazdaangelmazda Member Posts: 6
    The email address "" is not recognized. Please fix it and try again.
  • angelmazdaangelmazda Member Posts: 6
    Aloha Mike,

    Thank you so very much, my hubby finally fell asleep... has insomnia trying to get the car in working order..

    It's people LIKE YOU (helping others) that make this a Better World! :-)

    with the economy the way it is and our personal crisis; we gotta fix and cannot buy!!
    he will probably have me email you again tomorrow if that's ok with you....

    we are in Florida!!! The Atlantic Hawaii.......

    Ada & Angel
  • angelmazdaangelmazda Member Posts: 6
  • angelmazdaangelmazda Member Posts: 6

    so replacing the sparks and wires will take care of the p0301 issue,
    what shall we do about p0701 (leak?)maf sensor?
    and lastly, the p1522 ??? check wiring on solenoid? where are they located?

    Be Blessed
  • dawn40dawn40 Member Posts: 1
    My friend has a 2002 Mazda Millenia and he went out to start it for his wife - it started fine but when he turned the heater it died. He tried to started it again and it sounds like it wants to start but it doesn't. It has been a couple of weeks since it was started and we have just recently had temps in the teens and single digits.

    Could the gas line be froze?? Battery issue?? or Electrical??
  • abourqueabourque Member Posts: 5
    Can anyone help me... I have a 2000 Millenia S and it is running like s--t. It runs hot every once in a while and when I'm on the highway driving aprx. 65 miles per hour it is sputting/missing almost like gas isn't getting to the right place. The check engine like is on so I brought is to a local shop and they ran codes and what showed PO115, PO431, P1790. The guy told me he doesn't work on this type vehicle so I'm stuck. any ideas of what the codes mean and how I can get it fixed? Also, TCS OFF/ TCS light comes on every blue moon. sometimes only TCS OFF, sometimes both.thanks
  • abourqueabourque Member Posts: 5
    Hey I know it's been a while since you posted this but.... I have a 2000 Mazda Millenia S with this same code P0431. Same problem as you, local shop told me cat converter but the muffler shop told me it was in good shape, looked new some then another shop said pre-cat... talk about confusion is right. I'm lost and don't know what to do... you can email me at [email protected] or reply on this post. thanks
  • bobrkrbobrkr Member Posts: 2
    I purchased my 2002 Millenia S in 11/05. Every year since, I have had the same recurring prblm. The A/C will be working fine and all of sudden you get that stale, humid air feeling and realize it quit. The fan is still blowing but it's not cold air. Sometimes it will cycle and come back on but most times the engine has to be turned off before it will work again. This year it has happened the most which is several times a week. Previous years were like it would be great for several days to a few weeks at a time with no problem but eventually it would happen. The A/C has been looked at every year by a mechanic. 2 times they said the ever popular "Could not duplicate problem". 3 times (including this year) I was charged around 80.00 per visit because they said I was "A little low" on freon but no leak detected. Any suggestions? It's freaken hot this summer in Kansas. HELP!
  • bobrkrbobrkr Member Posts: 2
    How difficult is it (for the avg person) to replace the EGR Valve on a 2002 Millenia S? The part is approx 15.00 and the labor is approx 120.00ish. I am willing to try and do it myself if it's not too difficult.
  • wolverine50wolverine50 Member Posts: 2
    I just purchased a 2001 Mazda Millenium V6. with 100,000 miles. It ran good when purchased. Last week I began hearing heavy tapping noise coming from motor when I started the car. When I excellerate the tapping noice would go away or quiet at times. Other times the tapping would get worse. It has got to a point I cannot drive the car because of fear I will do permanent damage to the motor. Has anyone experienced this problem or have an idea of the what the issue could be?
  • mailly196mailly196 Member Posts: 2
    edited February 2011
    I have a Mazda 2002 Millenia and I recently came across this situation . My CEL came on and prior to it coming on I noticed I was getting a rough idle at times , actually a knocking every couple of seconds , would do it three or four times as I wait for green light . Also was getting a sluggish acceleration . I stopped in at a local Autozone , they plugged it up and a code P0431 came back / Catalyst System . I simply added Iso-Heet/Water Remover and Lucas Complete Fuel Treatment . After driving 25 miles the car runs smoother and no more CEL . Hope this may help anyone before running to a shop and throwing money away . Thank You . ;)
  • only1jeronly1jer Member Posts: 1
    ok, my car's been in the shop 3 times in the last 3 weeks!!! First codes P0421, 1250 and P1522 came up and the shop did some replacing of a couple valves or something like that then 10 miles into my drive home my check light came back on so brought it back and they decided that it was 2 o2sensors and 1 catalytic so they replaced those and then 20 miles into my drive it comes on again and this time they didnt give me any codes, just told me that the puter must be reading that the old unreplaced o2 sensors are bad now and that i should replace those!!! So instead I went to autozone and was told that it was now only code P0421 and i should look for leaks before anything else. They reset the computer and it was great! No check engine light for 2 days! Then tonight... BAM!! It's back on and auto zone says its P0421 and also P0400. So now i have a whacked catalytic converter and a egr problem!??!??!?!!??!! PLEASE SOMEONE OUT THERE SAY YOU'VE BEEN THROUGH THIS AND HAVE ANSWERS!!!!! PLEASE!
  • gizmosangizmosan Member Posts: 1
    Iv reached my limit with this car maybe someone here can help me out.
    Car idles perfectly but when put into drive, it reaches approx 2000 rmp the engine bogs down and doesn't allow me to speed up, going up hills is worst most of the time i end up slowing down. Mazda did some work on it then suggested it was the supercharger... Fail... I purchased a used supercharger and after the swap out the problem is exactly the same.. So to add to the mess, I attached a diagnostic computer to my car which I have done plenty of times before... except now when I unplug the cord (specifically the cord) from my car. It stalls out and will not turn back on until at least the cord is plugged back in. Iv tried all forms of plugging it in and out with and without a battery no luck

    When the car bogs down... sounds like its missing, with a crackling noise.
  • mullet6412mullet6412 Member Posts: 2
    My 02 Millenia S (Miller cycle engine) CEL mystery was eventually fixed by replacing the gas cap. At my dealer it was $125 (don't try using a cheap one from your local auto store; pry open your wallet and use the Mazda one -- apparently there's a sensor that relies upon NOT having a dried out gas cap seal). Go figure. :shades:
  • t2tt2t Member Posts: 7
    I have a 2002 Millenia, which we purchased brand new. It's not the "S", so I have the 2.5L engine. I currently have 162,000 miles on the car. The last 3 years has been a real pain at getting my arms around the EGR / Check Engine light issue. I'm not sure why this car is so problematic in regards to the CEL being on nearly constantly. People shouldn't have had to suffer so much with whatever defect is presently causing the EGR issues. If I were going to buy a used one today, I'd get a written agreement from the seller that if the CEL comes on within 90 days of purchase, then it's their dime to fix it for you. I suspect many of the used Millenias out there have had some recent maintenance to clear the light and the owner got ill from the bill, so they put the car up for sale.

    Don't get me wrong, I'm pleased that I've gotten this many miles out of the car. However, one should also expect to be somewhat free of a car from getting a CEL so frequently. I've done everything possible to cure my P0400 (Generic EGR Malfunction) code to completely go away and it did for about 30 days over a 3-year period, which was long enough for me to get my emissions inspection passed for the next 2 years (I have about 10 months left to go) and then I'll need another emissions inspection, but I doubt if I'll be dropping big bucks into the car so it will pass. I'm very fortunate that I can do 90% of the work on the vehicle myself. To date, here's all that's been done to try to resolve the EGR (P0400) issue:

    1) Cleaned the EGR valve of carbon.

    2) Cleaned out the EGR chambers in the intake manifold.

    3) Cleaned out the two "snake eyes" that hide behind the intake butterfly valve.

    4) Replaced all of my vacuum lines (about 25 feet, total)

    5) Replaced the 2 solenoids for the EGR system (Vent and Vacuum solenoids).

    6) Had the BG EGR process performed ($250.00 at a shop).

    7) I removed the intake manifold and took it to a machine shop to have it dipped int their
    parts cleaner tank and then pressure sprayed to clean out any carbon.

    8) I replaced the EGR valve with a know used working one.

    9) Re-installed the intake manifold, but the EGR issues didn't disappear.

    10) I took it to a shop to have them look into the issue further. They claimed I needed to have my EGR valve replaced. ($750.00 in parts and labor).

    11) I was happy that the issue seemed to be finally resolved, right? Wrong! I had my car inspected for emissions and it passed. Then, a week later, the CEL light was back on. It's been that way for the past 14 months as I really don't want to work anymore on the P0400 code. It's impossible to cure on my car. I don't think throwing more cash into it is the answer ... only to get frustrated.

    I don't see myself buying another Mazda product in the future. A bit too expensive to get parts for - if you can find them. Currently, it appears the front pre-cat is no longer on the market unless you go to the dealership and buy it. The rear pre-cat is available from about 2 or 3 other 3rd party manufacturers.

    The EGR valve costs $400 at the dealership and is about $300 from Mazda discount parts places on the Internet. When I had my Ford Taurus, the most I ever paid for an EGR valve was about $65.00.
  • TheMguy01TheMguy01 Member Posts: 4
    It could be one code triggering another code
  • TheMguy01TheMguy01 Member Posts: 4
    Ddi you replace your EGR Sensor?
  • t2tt2t Member Posts: 7
    "Ddi you replace your EGR Sensor?"

    Greetings. If I could ask more specifically - which component is the EGR sensor on the Millenia? I've checked my replaced solenoids for the EGR (Vent and Vacuum) and they are within spec in regards to Ohms.
  • t2tt2t Member Posts: 7
    Hi, Sorry about the delay in getting back to this topic. I didn't replace the EGR Sensor, as I don't believe the Millenia has one - even though they have at least 1/2 dozen solenoids.

    I suspect, though, what you're referring to on the Millenia might be what they call the MAP sensor. That is a device, mounted to the back of the engine on the firewall and has one vacuum tube running to it. I believe most of the MAP sensors that I've seen on Millenias were made by Mitsubishi.

    I should probably spend a Saturday morning going to a "Pick and Pay" junk yard to collect some items for potential replacement. Though, there is always the risk of getting a part that's no better than the one you're trying to replace.

    This past weekend, I did buy an universal DC power adapter, though. Using that with my Millenia service guide, some aligator clips and spare vaccum hose, I'm going to follow through with the proper test procedures to determine if the sensors and solenoids are all operating properly when a load is applied to them. This will keep my from buying an endless supply of parts that might not need replacing.
  • hugheduhughedu Member Posts: 1
    Hey Buddy, i had the same problem.... I was about to get crazy, I've spent 700.00 in the last 3 days. I took my milly it to the shop and they did a full tune up, cleaned whole EGR SYSTEM, changed some bad hooses. I changed my Break rotors and pads, and reset CEL, The mechanic told me that my EGR System was ok and wasn't any reason to replace it, That the CEL shouldn't light up again, I was happy for a couple of days, right after I went to the gas station and filled up the tank.. boom!!! the light came again.

    I was continuing doing some research and it looks like the GAS CAP...yeah... The Old Gas Cap is not hold the correct vapor pressure and its making the EGR Sensor to activate the signal...

    So I want to a Auto ZONE and bought a new $10.00 GAS CAP, after few hours, the CEL went off.. Im loving my car again.

    I've also been reading that this did't work with some cheap gas caps and some of the guys with the same problem were forced to buy the original gas cap from mazda $125.00 but it did fixed the problem just by replacing it.

    I wish I knew this very long time ago, because I've been paying under the table to get my Emission Inspection Passed.

    I hope this works for you. ;)
  • t2tt2t Member Posts: 7
    Your post does seem encouraging. I've gone through the whole EGR cleaning process to the minute detail and still had many issues. I also purchased a new gas cap from AutoZone that apparently worked for about 2 days - then, bam, the light was back on again. I confirmed I didn't have any bad hoses, too.

    With that being said, I hit 165,000 miles on my Millenia about a month ago. I was kind of getting to the point of feeling a bit frustrated with many weekends of having the hood up on my car to get things situated - oil leaks, valve cover gaskets, etc. So, I was able to buy myself a newer Buick LaCrosse. I posted my Milly on Craigslist for $1,200 and it sold within 10 minutes of being posted.

    I liked our Millenia a lot, but locating parts was becoming harder as time passed. Also, the dealership doesn't charge $125+ for a gas cap. I believe that it's somewhere in the range of only $25.00. However, if you buy from - the Millenia parts are discounted and I think their price for the replacement cap was only about $18.00. I'm not affiliated with them in any way, but have been very happy with their prices and service when I needed them for my true / authentic Mazda parts.

  • mullet6412mullet6412 Member Posts: 2
    Update to my previous post about changing out my gas cap to solve the CEL problem: After I questioned being billed $124 for a new gas cap at a Dallas metro area Mazda dealership, the service manager refunded me the $99 "diagnostic" fee. So yes, the OEM gas cap that says "Mazda" on it is actually only 25 bucks. And 3 months later still no CEL, so I'm happy.
  • t2tt2t Member Posts: 7
    Diagnostic fees ... Grrr. I can see where they're worthy at times if it will truly diagnose an issue - a small one, instead of replacing your motor. However, I feel that they're just another way for mechanics to generate revenue. Connecting a diagnostics tool and reading a few codes will take 5 minutes. Yet, you pay a minimum of 1 hour's worth of labor for it. Also, those "supply" fees and "disposal" fees can take a $25.00 oil change and make it go up to $40.00.

    However, the benefit in using the "true" Mazda cap is that you can continue to use the tether, if you like that feature. Some people who don't have a good memory will leave the gas station with their gas cap still sitting on top of the pumps.
  • jpland82jpland82 Lafayette,Louisiana Member Posts: 0
    Well I just got my Millenia S 2002 in January of 2015 found it with 45000 miles thought I got a good deal at 6500 basically in showroom condition then the 60000 mile service pack game come to find out it has two timing belts 2 water pumps and to serpentine belts brought it to the Mazda dealership here including a new alternator $2,900 now they did throw in showroom detailing to the car which was like oh what a hundred twenty bucks 2 brand new Yokohama tires 387 to new keys totally outrageous I think at a hundred twenty thousand miles she's going to get parked and wait for classic status but otherwise I absolutely love the vehicle and also my engine light is just coming on and
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