2009 Tacoma running rich

09taco

Does anyone have this condition??....My truck seems to be running rich, however the MPG still is around 15-16 city. The side of my truck is black above the exhaust pipe area. The side of truck has black carbon all over the side. Even the exhaust pipe is covered in black carbon build up. The service engine light is NOT on. I checked with toyota service dept. they said that's the way it is... I looked at other trucks just like mine and they don't have this condition. My truck only has 15,000miles all stock, no after market parts. Any suggestions would be very helpful!! Thanks

wwest

Other owners WASH their Tacomas more often..?

09taco

I do WASH my truck alot more than most others, I take very good care of this truck, not off road. just everyday typical driving conditions.. just for your info.
Just looking to see why the truck gives off black carbon... and to see if there is a correction for it.....
If you have nothing good worth saying, don't waste your time posting it on here!! must work for a toyota service department????

wwest

OIL...?

09taco

doesn't seem to be burning oil...I would say burning more gas than it should, I just checked got about 14 mpg city driving. I should be around 16city..no service lights on....the end of my tail pipe looks like a smoke stack off a old Mack Truck...which makes my back corner panel Black.
again this truck is very clean... TRD off road double cab V-6 auto..

66cad

Just got my Dbl Cab back from the Dealer, tells me this condition is normal on all Tacomas. Sometimes on startup I get a fair amount of smoke which I don't think is normal. Suggested I buy a chrome extension for the tail pipe to keep the black off the paint. Only had the vehicle 6 weeks ( second owner ), first import I've owned, not too impressed with Toyota Service so far.

Anyone experienced throttle sticking ( electronic fly by-wire ) on this vehicle? I've had a couple of instances where it does not want to throttle back, ECU has been modified for the brake overide.

busiris

Do you take a lot of short trips..... say 2-3 miles?

Even modern engines run richer until they approach normal operating temperature.

I have a 09 4-cyl Tacoma (15K miles) and have never noticed anything like what you have described...

It should be fairly easy to find a local garage that has an exhaust sensor used in tune-ups that can do an actual exhaust analysis, if you are so inclined to verify the "richness" coming out of the tailpipe...

Good luck!

09taco

that's something to think about...That might be something to check into. I do drive short trips on the weekends, and about 10-12 miles to work monday to friday..The truck seems to run okay, for now. But I think its not right to have this heavy black carbon on the side of a newer truck, people see this and say eewww. whats wrong with your truck? And again I keep my truck VERY clean.

roosterjon

Carbon is a normal byproduct of combustion. The "soot" you are refering to is pure carbon that is left over after the combustion of the hydrocarbons has occured in the combustion chamber. Other byproducts of the automotive engine include H20, C02, N0x, CO, et all. Because complete combustion is impossible - you will always have soemthing left over. A quick internet search of any model will reveal that a lot of people take notice of this condtion regardless of make or model. It is 100% normal - dont sweat it. If your engine light is off you really have nothing to worry about.
Yes I am a Toyota MDT.

popsavalon

I disagree with you, your answer sounds like a typical dealer service "brushoff". The problem that 09 taco is describing is not 100% normal, or even 10% normal, based on casual observation of other vehicles that I see.

I don't see "sooting" on my Tacoma, or my Avalon, either. I think the post about an exhaust gas analyzer would be a good place to start, because there is something definitely wrong, and it is not being indicated by the "check engine" light for whatever reason.

popsavalon

wwest, I am ashamed of you. You normally give a much more technical response to the problems that folks have.

roosterjon

With no MIL light on...... I will bet $1000.00 that your 09 Tacoma is operating 100% normal and you just can't accept that you are wrong. I deal with guys like you all day long. I will gladly put it on my 5 gas for no charge. I will even invite the engineer of your choice to come and be a witness. Does that sound like a brush off ?

popsavalon

Gas burners do not soot up the sides of a car if all is well, just saying.

Key in on the words "gas mileage is down", and "black exhaust smoke". I think that might indicate some sort of fuel problem. At least it did in all my years of engineering automobile fuel systems.

I have no doubt that you "deal" with folks that have legitimate problems every day.

wwest

Okay, is the Op's Tacoma burning oil and that's the source of the soot..?

wwest

Given the level of A/F ratio checking, forward oxygen and post-catalyst oxygen sensor, it's hard to believe that the idle or cruise A/F mixture could be rich. But during acceleration or the engine under load, uphill or towing, the engine runs intentionally rich and therefore switches to the MAF/IAT module sensors to control an enriched, ~12:1 A/F mixture.

The mixture is now being control via PRE-PROCESSING, ONLY, based on intake airflow rate/volume and the temperature of the intake airflow....

NO downstream A/F mixture "cross-checking" as happens during idle or cruise.

I would switch in, as a test, a new MAF/IAT module sensor set.

Second possibility would be a too sensitive knock/ping sensor. Your engine is not really likely to knock/ping in idle or cruise when the cylinders are nowhere near to getting a FULL A/F mixture charge, but WOT or nearby...?

If knock/ping occurs, even the slightest level (not aurally detectable), during acceleration or with the engine under a serious load level, the mixture will automatically be enriched, up to a certain level, to abate the knock/ping. The same method used to allow a modern day high compression engine to run on regular fuel.

wwest

Happy now...??

popsavalon

Yes, now we have got something to go on!

khergert

Mine is a 2009 Tacoma Regular cab, mt, 4wd, 2.7 motor. I too have the black exhaust. 3 dealers showed no interest, but Penske Toyota took me in and linked to the engine. All showed fine. Forward to January 2012, I'm at 40k miles, average 22 mpg and no drivability issues. I feel the oil is a bit dirty, but not excessive. Unrelated, my 2004 Tacoma xcab, auto, 4wd, 3.4 motor has a perfectly clean exhaust. So far, the exhaust soot is a cosmetic issue only.