Did a search, on here as well and couldn't find aything.

So there are 3 sensors total?......but what are the exact location names? I need to know which one "Bank 1, Sensor 2" is (that one threw PO137 ...Circuit Low Voltage).

And will this code make me fail the Aircare test? Do you fail it if you get ANY code? I also got thrown a P0335 (Crank shaft position sensor, A circuit)

 

That sensor is your down stream one. so the spacer did nothing. Either your sensor is bad or the cat is

http://www.justanswer.com/chevy/4vla...der-wheel.html

 

So you just said the Bank 1, Sensor 2 (that said low voltage).....is the after Cat sensor? (which is new)

And my spacer (non-fouler stack) did nothing??? How can that be? It's kept it from throwing the P0420 Cat code again. When before, the first time I erased that code, it came back after only 6km's. Now with the spacer and over 100km's, it still hasn't come back. And everybody who does this says it never throws the P0420 again. WTH?? The Cat is a new Walker, a week old.

 

look at the link. Maybe it was the punching it that did it. Clear them drive easy for 100 km and take it in

 

Thanks.......I was thinking of trying again. But easy this time with no flooring it.

And the specific sensor locations is driving me nuts. There's a diagram on here, but..........it says the AFTER Cat O2 sensor is B1S3, not B1S2, But then again, that diagram looks a bit different even though it was supposed to be a 2002 also (shows no smaller pre-cat thing........and the distance between the "Y" join and the Cat, is too short.......compared to mine).

This day insurance is killing me

 

Passed Aircare!

 

As for the sensor locations, it seems I've found that apparently difficult info myself. And of all places.............in my scanner tool's instruction manual:

BX SX being...

B1 is (at least on a "V" config. engine) always the side of engine that has cylinder #1.

B2, is always the opposite side of B1.

S1 is always front of the Cat.

S2 is always rear of the Cat.

 

The sensor numbers (Sx) are correct for your application, but not all applications.

S1 is always an engine fuel management sensor location which is the sensor located closest to the engine. S2/S3 are always emissions monitoring sensors. In the 96-97 trucks, S2 was actually a pre-cat sensor that monitored the Oxygen content in the exhaust prior to entering the cat while S3 was the post cat sensor. In 98, they did away with the pre-cat emissions monitoring sensor and kept the S3 naming for the post-cat sensor. Sometime in either 2001 or 2002, they changed the post-cat sensor to be S2.

All of this additional information I have posted in the past, but I'll expand here for a "one-stop shop" post.

96-97 Diagram:

98+ Diagram:


I edited the 98+ diagram to show the changes in the later production dates noted below:
98 thru late-2001 or early-2002:
1 - B1S3
2 - B1S1
3 - B2S1

late-2001/early-2002 thru end of production:
1 - B1S2
2 - B1S1
3 - B2S1

I will likely copy this information into a tech article just to make it easier to find for anyone looking for it at a later date.