On The Fence ...

[Camino LS6]

Oxygen sensor, I'm willing to bet.

[Intrepidation]

How many O2 sensors on their on those cars? Mine has 4. =/

[Camino LS6]

Not sure on the 3800s...

[Intrepidation]

Also, the car will usually throw a code (such as P0161 or P0159) if there's something wrong with a sensor.

MAF (or MAP) sensor might be something to look at as well...those can foul and not throw codes.

[Blake Noble]

I believe my car has either 3 or 4 O2 sensors. I want to say 3 because my car does not have dual catalytic converters, oddly enough, because it is my understanding that 1996+ had them. I'll have to reference that to make sure.

EDIT: Couldn't reference it, but I think there are 4 total; one on each manifold, one before and one after the cat. I think.

Edited January 29, 2010 by whiteknight

[SAmadei]

I believe my car has either 3 or 4 O2 sensors. I want to say 3 because my car does not have dual catalytic converters, oddly enough, because it is my understanding that 1996+ had them. I'll have to reference that to make sure.

EDIT: Couldn't reference it, but I think there are 4 total; one on each manifold, one before and one after the cat. I think.

Its a V6... it should have 2... one before and one after the cat. Replace the front one... it is the one that affects the engine management. The rear one merely tests the efficiency of the cat.

Edit: DF, You only get a code for the O2 sensor if it really goes bad... but they can become quite worn and ineffective without setting a code.

Edited January 29, 2010 by SAmadei

[Intrepidation]

If it has 2 cats it'll most likely have 4 sensors, one pre cat one post cat, as said.

[Blake Noble]

Finally found my reference materials and regarding the dual cats, LT/LS cars had them, not the V6 cars. Ditto my incorrect O2 sensor count. :facepalm:

[Intrepidation]

Lucky for you, I dunno what they cost for your car but for me they're $100 a pop.

[Blake Noble]

Cheapest O2 sensor for my car is sixty-something bucks. That's a Bosch with OEM style plugs vs. universal plugs. A Denso will run around the price you mentioned.

Edited January 29, 2010 by whiteknight

[Intrepidation]

Well I dunno about GM cars, but with LH cars, any other brand other than the OEM ones cause problems...you should check and see if Bosch etc. work ok.

[Blake Noble]

From what I understand Denso sensors are the replacement to buy that has the least amount of issues and are better than stock.

Note: Remember how I mentioned the exhaust smelled like the air/fuel ratio was a little lean? Well, now the smell is becoming more and more noticeable ...

Edited January 29, 2010 by whiteknight

[SAmadei]

Well I dunno about GM cars, but with LH cars, any other brand other than the OEM ones cause problems...you should check and see if Bosch etc. work ok.

Bosch can he questionable in alot of GM cars... B-bods, H-bods. Not sure about F-bods, but it seems to reason...

[vonVeezelsnider]

Bosch can he questionable in alot of GM cars... B-bods, H-bods. Not sure about F-bods, but it seems to reason...

I've heard that as well.

[daves87rs]

Bosch can he questionable in alot of GM cars... B-bods, H-bods. Not sure about F-bods, but it seems to reason...

Yep.

[Blake Noble]

It's 80 bucks at Jack Burford Chevrolet to run diagnostics. No refunds if they can't repair the problem, no refunds if they do repair the problem.

There's no way I would drive this car to a dealership in the Lexington area. The car is running so bad right now, I wouldn't trust it on a trip down the street.

[Blake Noble]

Went out on a limb and replaced the ICM. That fixed the problem. Except now a new problem has made itself known: the muffler is rattling like a tin can. Oh well. I was going to put a Flowmaster cat-back exhaust system on it anyway.

Edited February 4, 2010 by whiteknight

[67impss]

whiteknight

I just found the topic. I'm glad it was the ICM but I was leaning tward the primary circuit of the 1/4 coil pac many times either primary voltage or ground problems are the culprit. I'd also look at other mufflers as to their HP/Torque increase compared to the $ cost. Glad it didn't beat ya

[Blake Noble]

whiteknight

I just found the topic. I'm glad it was the ICM but I was leaning tward the primary circuit of the 1/4 coil pac many times either primary voltage or ground problems are the culprit. I'd also look at other mufflers as to their HP/Torque increase compared to the $ cost. Glad it didn't beat ya

Very good point on the exhaust system I didn't give a lot of serious thought about. I wonder if the Borla system would yield more HP gains versus the Flowmaster system.

The Borla system sounds awesome too; it can actually at idle give the V6 a similar exhaust note to a small V8. It only really sounds like a 6er when you rev it up wayyyy high.

I'll have to compare the two ...

Edited February 5, 2010 by whiteknight