This is a continuation of a thread I made last week. Basically, SES light, p0420, bad cat, 80k mile warranty. Code read cat efficiency below threshold (bank 1). They told me that the code was from the o2 sensor and the cat so they were going to replace it under warranty. However, I made a comment about there being a rattle which I thought was the cat. They said it was the o2, not the cat, so they charged me $60 for that even though I never said I want them to inspect for the sound, I was just giving them info to help. I argued and made a commotion in the service area that they were ripping me off, but to no avail. Big deal, figure I paid $60 to learn a valuable lesson.

Anyway, the reciept was that they replaced the bank 1 cat. the obdII sensor said bank 1 was the problem as well ( the book states that bank 1 is the passenger side). As long as I can remember, bank 1 contains the #1 cylinder, which since the banks are offset, is always the bank closest to the front. Every v8 I've ever seen has bank one on the passenger side, which correlates with the obdII book. Imagine my suprise when I get under the car and see that the cat replaced is on the driver side, the wrong side. Now before I jump on the dealers case again, I do notice that the ls1 has the driver side bank more forward. So whats the deal?! Someone mentioned that the 01's had a TSB about the passenger side cat going out, but didn't state which bank it is considered. So who's right here, the dealer or me? I'm so fed up with them that I would LOVE to go down there and lay into them that they screwed up again. Also, I need to know because I'm going to replace the o2 on bank 1 and need to know which side. There's much more to this dealership story, but I'll post it in the lounge. Regardless, any Bay Area, CA f body owners, I STRONGLY discourage you from going to Putnam Chevrolet in Burlingame.

 

As far as I am aware, Drivers is Bank 1 and Pasengers is Bank 2. A friend was throwing a code bank 1 sensor 2 not switching. It was a bad 02 sim on the drivers side. So I would say they were correct.

 

Well is this a characteristic on only the ls1. That would make it differant from every other V6/8 I have ever heard of. Bank one is always on the passenger side. Besides, the TSB says it is the passenger side, and a lot of people say they're passenger side goes out. My car has 40k on it. The chances are slim for a the "good" cat to go out first at such low mileage.

 

OK, just checked and I found out the firing order is differant on LS1s. My mistake. Last question. my cars performance dropped a lot and I thought it was because the PCM changed something (lean or rich) because of the cat or code, decreasing performance. I got it back and I can't really tell a diffearnce. DOes it take awhile to reset or am I just imagining things?

 

Reset it yourself.
turn key on NOT starting the motor
under the hood pull the PCM ign & PCM batt fuses
wait about 10 minutes
turn key off
reinsert fuses

 

they told me they replaced the passenger side cat bank 1 also with the P0420 code. i put it on my lift and behold the driver's cat was nice and shiny.

 

Have them check the Air Pump....

I just got done with an issue similar to this, throwing a code.
The delaer replaced my passenger side cat.
Still the code would come back...
They found out the Air Pump was screwed up.
They fixed it and weeks later car seems to be fine.
I will look at their paper work and see what code it was throwing.

 

Paper work says they replaced:
part number
12565503
Not sure if this will help....

 

some sort of valve
http://sdpc2000.com/search.asp?searc...5503&doQuery=1

 

well, i havent gotten a code other than the 0420, but ill check out the air pump after i figure this mess with the cat. however, it seems to be working fine. i hear a little whine on cold startup, but it goes away in a bit. anyway, someone mentioned a TSB about 01 fbods having bad pass. cats. i mentioned this to a more performance oriented dealer SA. he looked it up but couldnt find anything. he asked if i could find it, they would do it. i looked through google but couldnt find anything. anyone have anymore info on the TSB?

 

bank one is where the number one cylinder is and that is always on the driver side in a gm vehicle. unless it is a front wheel drive caddy or something

 

no, i could of swore that my old 350 had the #1 on the passenger side. also, the obd2 manual had a glossary that said bank 1 was the pass. side. of course, that book is a generalization of every obd2 vehicle out there. thats what tripped me up until i read that the engineers reversed the firing order to reduce vibration, which is why #1 is on the driver side now.

 

#1 has always been on the driver's front. still is. left bank (driver) front to rear is 1,3,5,7. right bank (passenger) front to rear is 2,4,6,8.

 

Bank 1 driver side. Bank 2 passenger side. Got that from the F body manual written by GM. 3000 pages of the most dry material you could ever read, but a must have fo a Camaro owner.

305s from the early 90s have the cylinder numbers reversed. Other than that, it's as mrr23 said.

It is very common for the cats to crap out on these cars. I've gone through both cats and aft O2 sensors within the first 30000 miles. That was when the car was stock. I'm at 65000 miles and have code 0420 pop up again. There was a bad batch of cats out of the factory for 00 and 01 f-bodies and Cavaliers. That may be the TSB you heard of. Don't know what's wrong now.

I never knew about the air pump. I'll have to check that out. I think my driver side check valve is acting up.

 

Yeah, cylinder numbering has nothing to do with firing order. In every gm vehicle I have owned (even the 2.8 gmc jimmy I had) the cylinders are numbered left to right front to back as you sit in the drivers seat. In front wheel drive cars they are numbered the same if you were to turn the engine so it sat in there the right way. The number first cylinder to fire in the firing order may be on the passenger side but not the number one cylinder.