New Here...quick Question?

[DSN46]

Howdy,

 

Just purchased a 2002 Tahoe LT 4X4. I love it, but there is a problem I'm hoping someone here can help me with...

 

I have never owned a "California Package" vehicle. I'm from Missouri and now live in Florida. This vehicle keeps throwing the "low voltage bank 2 O2 sensor" code.

I was told, and then read in the manual, that using fuel other than California standard fuel in this vehicle could cause this to happen... nobody I know can tell me what to do.

I can't drive around with the "Service Engine Soon" light on all the time!

 

Is there a way to take this engine BACK to normal so I can use the gas in this state?

 

I'm new here and I like what I see so far. A lot of knowledge on this board. I come from the Jeep world (Just Empty Every Pocket) and they have quite an extensive forum base also. I hope the GM world is the same.

 

Thank you for any help.

 

James

[redsled2007]

Being from California, what is "California standard fuel"? Northern Cali has it's own blend and southern has it's own also, and i would imagine that there's a few more that I don't know off hand.

 

If that's true why doesn't all cars from California throw this code when they leave the state?

 

Can't help with the proplem but wouldn't it just be a reprogram of the computer?

[Mark_in_Tulsa]

All gas sold in the US is fine now. I forget what it was called. Teir 1 or something like that.

[redvett]

All GM vehicles are 50 states compliant, the only change or CA maybe an additional AIR pump for startup emissions.

Your vehicle has a problem and if you have the code problem fixed you should be OK.

[DSN46]

Thank you for the replies.

 

I have done some more research on the truck and found that the previous owner has had aftermarket CATS put on it. Is it possible that the aftermarket CATS dont offer enough restriction therefore not allowing the O2 sensors to heat up like they are supposed to?

 

As for the California emmissions thing? Don't know a thing about Tahoes yet... tryin to learn. I know that with Jeeps and Yotas, they get 2 CATS instead of one like everyone else in the country... so when I was told that the fuel thing may be an issue by friends, I thought I would come here and ask.

 

Thanks again.

 

James

[D&SYukonDenali]

How many miles are on the vechile? It would be my best guess that you need to replace the O2 sensors (maybe all 4) or start with makeing sure they a securely connected both on the sensor end and on the electrical end. O2 sensors will start to go around 100,000 miles.

[D&SYukonDenali]

Forgot to mention, there should be 4 O2 sensors, 2 pre-cat and 2 post-cat.

[DSN46]

Thank you for your suggestions!

 

I have been out crawling around under it. There has been a whole new exhaust system (from the headers back) put on this truck recently.

I noticed that on the passanger side, where the down pipe meets the header, there is about a 1/4 to 1/2 inch gap all the way around. It's as if someone couldnt get the bolts to cinch up all the way. They had filled this gap with RTV Red, which is now useless and falling out. Do you think that this could be leaking enough that it would throw the code? The code said "bank 2". Is the passanger side "bank 2"?

 

Thank you again for all the help. I'm trying to get this baby up and running to my standards as soon as I can.

 

Oh yeah, it has 55,000 miles.

 

James

[redvett]

You can have no leaks in the exhaust system or you will get acode for lean condition.

Fix the leak and it should solve your problem.

 

Thank you for your suggestions!

 

I have been out crawling around under it. There has been a whole new exhaust system (from the headers back) put on this truck recently.

I noticed that on the passanger side, where the down pipe meets the header, there is about a 1/4 to 1/2 inch gap all the way around. It's as if someone couldnt get the bolts to cinch up all the way. They had filled this gap with RTV Red, which is now useless and falling out. Do you think that this could be leaking enough that it would throw the code? The code said "bank 2". Is the passanger side "bank 2"?

 

Thank you again for all the help. I'm trying to get this baby up and running to my standards as soon as I can.

 

Oh yeah, it has 55,000 miles.

 

James

[DSN46]

Thanks redvett.

 

Gonna try to cinch the bolts up tight myself first. I have a compressor and impact wrench... have done most of my own wrenching my whole life....

I just hope that I don't jack-up the bolts or snap one off or something!

If I can't get them, then I'll take it to the exhaust shop and let them play with it.

 

I'll let you know if this is the fix in case someone else is searching this same problem down the line.

 

James

[redvett]

I would put a good rust buster on the fastners and use a ratchet so you can feel the amount of torque your applying.

 

Thanks redvett.

 

Gonna try to cinch the bolts up tight myself first. I have a compressor and impact wrench... have done most of my own wrenching my whole life....

I just hope that I don't jack-up the bolts or snap one off or something!

If I can't get them, then I'll take it to the exhaust shop and let them play with it.

 

I'll let you know if this is the fix in case someone else is searching this same problem down the line.

 

James

[desrtrat]

fix the leak...

 

CA. package for emissions is mostly recalibrating the pcm to meet CA. HC/CO standards. the gas we are FORCED to use here in CA is a 10% Ethanol mix or what some call winter gas. the only thing you have to worry about is the 1.5+ better mpg you will get from NOT HAVING TO USE IT..

 

[DSN46]

Today I just got a new code:

 

P0420... Bank 1...

 

Man.. I gotta find out what the problem is. I don't want to throw parts at it until I find out what the cause is. I dont have the equipment to diagnose O2 sensors to see the wavelength of the signal and all...

 

I guess it's off to the dealer to find out. (sigh)

 

Thanks for everything and I will post back with results.

 

James

[Zembonez]

Today I just got a new code:

 

P0420... Bank 1...

 

Man.. I gotta find out what the problem is. I don't want to throw parts at it until I find out what the cause is. I dont have the equipment to diagnose O2 sensors to see the wavelength of the signal and all...

 

I guess it's off to the dealer to find out. (sigh)

 

Thanks for everything and I will post back with results.

 

James

If nothing else... pay the dealer to diagnose it and fix it yourself. Might well be worth it.

 

Good luck and post your results here.