My check engine light turned "On" on my Acura TL 2002. I took it to the dealer and he said he replaced my Catylitic Converter with a used one. I drove away and the next day the check engine light came back on. PEP Boys told me that the OBD II code was P0420. I took my car back to the Acura dealer and he read P0420 again and replaced the converter with a new one. I drove away again and before I got home the damn light turned back on. I now have $941 put into this problem. I was oundering if it could be the regular gas I put in. I the big mistake to fill up my tank with regular unleaded gas. Could this be the cause? Could it be the regular gas does not get my exaust hot enough to burn the gases and my sensors are misreading cousing my check engine light to come on? What else might be wrong?

 

if it continues to come on it may be either faulty O2 sensors or a ECU problem (you also shouldnt be running regular, but it shouldnt be causing this issue) Your dealer should have figured this out after teh replacement didnt work

 

Lets do this a step at a time
You took the car to the dealer on good faith they would diagnose and repair your car.
For reasons unknown they put a USED cat on your car- very odd to do in my experience
Then they put a NEW cat on- so you should have been creditied for the used one since that was not the right fix.
Now there is still a problem.
When they took your original cat off they should have inspected it because they must fill out a FEDERAL form why it was replaced.
Those are guaranteed for 5 years 50 thousand miles and you are probably not much over that anyway. Most cats go a long time
They should check the items fsttyms says- he knows these cars

The Dealer carries a higher level or responsibilty to CORRECTLY diagnose and repair ACURA cars because they represent the company.
Its like professionals in many fields who are held to a higher standard because of their training and alleged expertise.

So they still need a fair chance to redeem themselves- you need to speak direct and IN PERSON to the Service MANAGER about the problem

A call to Acura Customer Care is due now too
1-800-382-2238 x5 6a-5p pacific time m-f
Tell them whats going on- they will be in immediate contact with the dealer and usually you get a call- sorry terrible mistake, fixing it now, and in your case some adjustment about the cat cost if it was even needed

To quick fix the current gas- Lucas fuel cleaner can be added to the tank at 1.75 OZ per Gallon of fuel- that will raise it 3 octane points- thats from Lucas tech help guy
Buy the quart $8 or gallon 22$ bottle
Other octane boosters will work - I have no data for them

 

I went to autozone today and bought 1 bottle of Lucas octane booster and filled up my tank with Premium gas. I also has them reset my check engine light. Before they reset it I asked them to read the OBDII code and it read P0420 again. The light has not come back on. I will wait to expend this gas tank and refill with premium gas again without Lucas booster and see if the light comes back on. I will post my results.

 

Well, my CEL came back on after I filled up with premium and added the octane booster. So I took the car back to the acura dealership and they said that Cat and O2 sensors are fine, so they troubleshooted to find out what the cause might be. They found a bad ground wire on the engine fan that might be causing the computer to act funny. They told me th drive it and maybe it will not come back on. But it did, as soon as I got home the light came on again. The dealer told me that the car has been in an accident and now they will not cover the 8/80K warranty, so now it is on my nickel to fix the problem. Does anybody know what else it can be causing my CEL to come on?

 

Brewgod,

I would find another dealer. Where are you located? How many miles on the car? If fsttyms1 suggests O2 sensors or ECU, have a competent mechanic look at the O2 sensors then consider a known good unit ECU.

Or you could take it back to the current dealer and have them rotate the tires, vacuum the interior and then suggest the problem is fixed.

I'm not a fan of dealer shops, obviously. I hate to see "Easter Egging," replacing part after part until the problem is fixed, then saying that all the parts were broken and needed replacement.

Miner

 

What would a known ECU cost and what kind?

 

I would highly recommend finding another dealer. That one sounds Very Incompetent! Any decent dealer would have tried some of the things i stated (like swapping in a known good ecu-as its part of the test procedure)

I would also think about making a call to acura corporate about this dealer and their lack of willingness to actually find and solve this issue and trying to pin it on something else

 

The dealer has actually been good. They gave a loaner car until the find the problem at no charge. But who knows if they will charge once they find it. I asked them if it could be the computer malfunctioning and they said no because the computer has its own error code and that is not coming up. They told me today that they think it might be a faulty cat they installed because that is the only error code that keeps showing up. They are ordering a another new cat to be installed tomorrow. I will keep you posted.

 

Faulty cat- thats a good one! You mean the 2 he tried so far were both defect and the tech is so bad they cant figure out the codes- somethings wrong and they are BSing you in a big way

Was your car a SALVAGE title- thats the only way they can deny warranty by saying it was in an accident
Salvage titles get nothing from the dealer- why isnt your car at a good private shop?