cat and/or O2 sensor
 

our CEL has been on with a code (can't remember #) for the cat. car seems to run fine,plenty of power but gas mileage has dropped some. could it be a O2 sensor causing it? if it is the cat,where is a good place to get one? can I do it myself?

Please try to get us the fault code number so we can help more.

I will try to get the code from Knechts tomorrow (Sunday) after work.

Code 4-4-3?

Quote from the factory manual:

Code 4-4-3 (TWC* Efficiency); *I believe TWC = Three Way Cat
1) Check for other codes. If any code for misfiring is stored
(Codes 4-5-1, 4-5-2, 4-5-3, 4-5-4, 4-5-5, 5-4-2, 5-4-3, 5-5-1, 5-5-2,
5-5-3, 5-5-4, 5-5-5, 5-4-4 or 5-4-5) perform that testing first. If
Codes 4-3-5 or 4-3-6 are stored, perform testing for that code first.
If none of the above codes are stored, go to next step.
2) Perform a compression check on all cylinders. Repair as
necessary. If compression is okay, go to next step.
3) Check for air leakage in intake system. Repair as
necessary. If there is no air leakage in intake system, check for air
leakage in exhaust system. Repair as necessary. If there is no air
leakage in exhaust system, check fuel and residual pressure. Repair as
necessary.

It seems to me the trouble is either in the fuel control or O2 sensor, dumping excessive fuel into the combustion chamber. If the cat was shot, you would have noticed:

- Rattling noise (depending on the type of the cat).
- Rotten egg smell out of the tail pipe.
- Loss of power/vehicle speed does not rise at certain point.
- Out-of-spec emissions.

I would double check the code as suggested by Tech.


JPN

The code I got was P0117 something to do with coolant. I don't know what is going on with car,drive it till it dies I guess.

P0177 is engine coolant temp sensor code.
Replace the ECT and thermostat and that should fix it.

I was going to replace the temp sensor and t-stat when I was having the problems with the engine revving by it's self,but that problem just kinda went away. they turned off the CEL,guess I will see if it comes back on and what the code is this time.

2 days,and the CEL has stayed off. the last couple times it came back on before I got home from Knechts. now it will come on in the morning since I mentioned it here!