I recently had my check engine light come on, H2 has 64k on it, so I decided to bring it to autozone and they hooked up the computer and read the codes for me. The codes were 2 seperate O2 sensors and it said bank1 and bank2?? Well the problem is it seems like my hummer burned almost a half tank today and I only drove maybe 30 miles. Can these sensors really do that? and what is this bank1 and bank2 thing, the dam things were $120 each so now I gotta wait a week till payday, what do you guys think?

 

I believe that bank 1 is the side that has the number 1 cylinder on it. If your o2 sensors are bad on bank 1 and bank 2 they will be on both the driver side and passenger side as well.

 

When I look under the H2 I see 4 O2 sensors, 2 on each side, do you think I need all 4 replaced?

 

did the code say which sensor? you have 2 per exhaust, one below the manifold and one after the cat converter. do you remember what the codes were, that may help determine which ones are throwing the code. considering this is part of the emission control system, it should be covered under the 5 year warranty for emissions systems.

 

It should say Bank 1, sensor 1 or bank 1 sensor 2.

If you are having fuel problems, it is probably sensor 1. The ones behind the cat really do nothing but let you know if the cats are working.

But Shorty is right.............It should be covered.

 

Also, if you had a misfire or a bad tank of gas, it could set those codes. I would first clear the light by unhooking the battery for a while. Then run a tank of gas with a good fuel cleaner in it, and see if the light tags again.

 

Great info on the warranty! I never even thought abut that, Its a 2003 so its gonn abe borderline about that, but definately worth a try, I am gonna bring it back and get the exact codes and write them down, I also tried the unhooking the battery for 10 minutes but the lights were back on when I started the car. Thank for all the info, I like this forum