Hi all.
I have moved from Canada to California. I own a 2002 Chevrolet Avalanche 2500 model with the 8.1L motor.
While trying to get the vehicle certified for use in California I took it to a DMV referee whose documentation shows that it should have two O2 sensors after the catalytic converters, one on each pipe 4-6 inches after the cat. These post cat O2 sensors are not on the vehicle. I contacted GM and they faxed me a diagram showing where the post cat O2 sensors should be and they are not there. What is there is a cap of some kind which could be unscrewed so that an O2 sensor could be put in.
I bought the vehicle new. The emissions equipment have never been touched. The cats/muffler/exhaust have never been touched and are all completely stock. The vehicle passes smog testing both in California and in Canada.
I would like to know if forum readers who purchased a 2002 Chevy Truck in California with the 8.1L motor have these two post cat O2 sensors installed or not.
GM documentation says there should be four sensors total on my Avalanche, two pre cat and two post cat but my vehicle only has the two pre-cat O2 sensors and the post cats are absent.
Is anyone out there willing to crawl underneath their 2002 Chevy Truck with 8.1L motor and tell me if they have post cat O2 sensors?
If you are, thanks in advance!

Failing any corroborating evidence, does anyone have any advice on how I can get this vehicle imported and registered for use in California, given that the DMV referee thinks it should have two post cat O2 sensors?

Blake

 

Well the thing with California is, which you are probably aware of, is that their emissions standard are considerably more strict than most of the other states in America. Because of this, car manufacturers offer different emissions packages for cars sold in California.

Considering your truck is from Canada, the California emissions package is not installed on your truck. Personally, I would drive have an exhaust shop drill and weld on nuts to hold the 02 sensors in the exhaust stream. Do it just like GM said, 4-6" after the cat.

After your exhaust is ready for the O2 sensors, I would contact GM again and have a dealership install the appropriate wiring and possibly PCM work.

With it all said and done, I'm wondering if it wouldn't be easier and cheaper to get a truck from California that's already setup for their emissions regulations, instead of import your own, and convert it. Plus a truck from here will have a MPH speedo versus a KPH speedo :P

 

Thanks for you reply.
The pipes after the cat already have the fitting to put an O2 sensor into - no cutting or welding necessary. I could just procure some sensors and get them hooked up, except the dealer didn't know how to do the PCM work. I'll talk to them about that again ...
The truck, as purchased stock in Canada, has the appropriate sticker for California already. I think because the 8.1L motor was special and rare option, they only made one option - the California option because its the most difficult to pass. It is very expensive for companies to support multiple options on any product line so I can see them just making all 8.1L Avalanches in 2002 meet California regulations.
I'm trying to find someone else who has the 8.1L motor in a 2002 who can confirm that they also only have the two O2 sensors pre cat and that the post cat O2 sensors are also missing from their vehicle. If I can find this evidence to corroborate my story maybe the DMV referee will just give me a pass as is. The vehicle is stock. I know it! I'm too cheap to do any mods and I am the original owner. I bought it off the lot brand new.
Trucks like this actually sell at a premium in Canada to the US so I could probably drive it back and sell it there, fly back to Cali, buy the same one here and profit a bit. I may end up doing that in the end, but my five year old kid is very attached to this truck. The flat part over the bed is fun to play on apparently....

 

i have an 01' silverado with the 8.1 and it doesn't look like there is a spot for the sensor after the cats. i will look again a little later when the ground dries up a little. i looked under and didn't see any but i will crawl under a little later and let you know what i find....