O2 sensor code, ???'s for GM mechanics

[glock35ipsc]

02 GMC 1500HD 6.0L. A few months ago, I got a trouble code (can't remember the exact code at the moment, P0157 or P0159, something like that), but it was low voltage, sensor 2, bank 2 (O2 sensor after the cat, pass side). OK, I replaced that sensor, reset the computer, and all was well until the next time I drove it. Pulled the snowmobiles, and about 100 miles into the trip, check engine light came on again. Same code.

This part didn't hit me until yesterday. Before I ever got a light coming on, the far rear pass side tailpipe hanger broke, who know how many miles I put on it while it was broke. When I noticed it, I was in Vernal, Utah. A quick trip to the local hardware store, and it was fixed with standard issue mechanics wire!

Forgot about it again (this isn't my daily driver) until I walked around the truck one day and saw that the wire had broke. OK, back in the shop and weld the hanger back on.

Next trip, light comes on again. Get home, clear it out. Several days later, I crawl under the truck to get my daughters toy and notice that the back of the turbo muffler is cracked BADLY from the tailpipe hanging off of it!!!

Now, I know an exhaust leak will throw the code I was receiving, but mostly from manifold leaks and such ahead of the sensor. Will it do the same if I have a leak downstream of the sensor? I think this is my problem, but wanted other opinions too.

Thanks!
Bob

[glock35ipsc]

ttt

[Gremlinafteru]

Leaks down stream wont matter...because once it goes past the sensor it cant back up. I had a check engine on my truck(GMC 1500 5.3) on my rear sensors...but the kicker on mine is i have no cats, so there goin to read wrong, but i reset my computer and it went away...have no problems with it anymore...

Hunter