Well for the past month i have been driving with the serivice engine light on. It was for the o2 after the Catalytic Converter. car as 65k miles on it.

And lately sometimes the light will be OFF... It is normally for the whole trip then next time i start it up it will be on again. The far seems to be running fine.

I have posted on here about it before and someone from the site sent me an e-mail telling me that if i just replace the o2 i will just be replacing it again, and that i have to replace the catalytic converter too. Or the o2 will just go right out again and it was a common problem with LT1's that he has had at the dealership. Now Thinks that i have noticed and think that it might also be part of the problem is.
1. It is running rich. Whenever its reved quick it will shoot out black smoke, and when i capped it the other day it shot of i'm guessing carbon from the exhaust onto the ground. and left a black circle around the cut out cap that was capping it.

2. When ever i shut it off ive have noticed a LITTLE bit of what looks like white smoke comming out of the tips of my car. And this was with running the whole trip with the cut out uncapped.

Now for the questions.
1. Do i really need to replace the catalytic converter or just the o2 or go ahead and replace both the o2's?

2. Is there a way to gutt the cat. untell i get a new cat. Like do i have to cut anything to get to it and poke out the stuff inside and is there really a point in just gutting 1 cat. (rides a 97)?

3. Why is the light going off?????

4. Will this Seafoam stuff i hear about help? Since it's been running rich for a long time and clean out all that carbon.
I thinks thats all i can remember for right now might add more later but thanks for any help/replies.

 

Do you remember the specific trouble code? There are codes that cover sensor activity, sensor heater operation, cat efficiency, high voltage, low voltage, etc. Without the exact code, you are only guessing. Which bank of the engine is it for - left or right?

If the code was for "low convertor efficiency", it could be either the cat or the sensor. One way to check is to swap the two after-cat sensors side-to-side. If the problem follows the sensor, its a sensor problem. If the problems stays on the bank it was originally on, its the cat or possibly a wiring problem.

Need more info to help you out.

 

here was the what came up when i got it scanned a month or 2 ago. Thru the same code twice.

141
Heater circuit malfunction
(bank 1 sensor 2)

do you think i should get it rescanned? ALso i need a special socket to remove the O2's right..?

 

AutoZone will scan it for free and just write down the code but their tool will tell you what it is. Bank 1 (driver side) Sensor 2 (after cat 02 sensor) heater circuit malfunction (it's a bad 02 sensor) bottom line. Change it.

My understanding is the after-cat 02 sensors are backups for the pre-cat 02 sensors. So if they quit working in the front they will still relay oxygen conditions to the PCM to maintain your Fuel Trim Tables. If your on a budget just replace the driver after cat 02 and see how it runs, if you want to follow the book, change all 4 02 sensors and I'd be willing to bet your car will run like a champ. For insurance hit a muffler shop and let them check your cat pressure.