Crown Vic computer issue fix by reprogramming?

abooeesa

I've found a 2004 Crown Vic to buy, but I took it to my mechanic to run a computer check and they flagged the following issues:

1) Oxygen Sensor
2) Catalyst
3) MAF Sensor Performance

They said they can fix these simply by re-programming the computer. I don't speak their language well so I can't clarify very easily. Do they really mean they can fix them by re-programming the computer, or do they mean that they will just hide the issues? They want $100 for the work.

thecardoc3

Software updates fix a lot of problems, they do not however fix every problem. When dealing with a car that has trouble codes stored in it and the manufacturer has released software that addresses those codes there are two paths that can be taken. The first is to do the update and then troubleshoot what ever codes return, if any. The second would be to spend time performing diagnostics first and see where that leads. Either one of the two paths is going to be more correct for a given vehicle and there is no way to know in advance. You could even have a car where the software update is the correct some of the codes, and normal diagnostics would be correct for rest.

tjc78

Now many miles on the car?

MAF might just need a shot of cleaner, catalyst could be nothing and just related to a bad O2 sensor.

My opinion is get what the actual codes are look them up to see what you are dealing with

Could be just a dirty MAF causing a rich condition. Fix one thing and it may clear the other codes.

Bottom line you need more info. $100 sounds light to fix it.

How is it running?

abooeesa

It's running a bit rough, spark plugs 4 and 5 need replacing and it needs a tune-up and might need "coils" (not sure what that is either)

150k miles. Middle East model

abooeesa

Actually it probably isn't a Middle East model because the speedo is in MPH. It would have been imported privately.

tjc78

Well... that tells another story. These are known for cracking intake manifolds. Many times they fail and weep just enough to flood the plug wells and coils causing a misfire. Check all around the intake for leaks.

What I would do is swap the coil with another that is firing and see if the misfire follows. If it does then you know the coil is bad.

You can get a whole set of coils fairly in expensively on Ebay for the 4.6

Sounds like this one certainly has some needs, but 04 is a good year. Last year before DBW and they fixed the soft axle issue.

abooeesa

I hope this one doesn't have a soft axel...

It's got a problem with the rear diff making a noise after 40-50mph. It will cost me 400 - 600 USD to fix that too.

Am I buying a lemon, or will this thing run and run once I fix up these issues?

abooeesa

Also the front suspension squeaks when you get in the car. What could that be?

abooeesa

btw I've done the deal to buy the car for $1,800. Seems mad when I see that written down...

elias

yes reprogramming the computer will just mask the issues temporarily. all the named parts are wear items known to fail sooner or later. swap the O2 sensor and MAF sensor and hope the catalyst code doesn't return. be prepared to deal with DOA MAF sensors if you get "rebuilt". you can test MAF sensor by running engine without it. . If car runs better with MAF disconnected definitely get a new MAF. catalytic converter(s) may be 3x more than the O2 & MAF sensors combined but can probably be cut-out for "off road" or UAE use. the front & rear suspension probably needs a swap of most every bushing and tie-rod and control arm - if you swap one old squeaky part, another old part will immediately start squeaking.

elias

ps, the rear diff hopefully just needs a normal service & new heavy/80-weight gear oil or whatever is spec'd . $200 or $300 at a dealer, max. if its a limited slip diff the clutches could be wrecked so maybe that would be $400 - $600 (or worse - maybe find salvage yard diff/gears to swap in that case). ps - to celebrate your vehicle I recommend watching the movie _Blues Brothers_ .