Advanced Engineering Tech - O2 sensors keep dieing, need help?

I have a 2000 ss with longtubes and true duals. When the factory o2 's went out I replaced them with some denso o2's and everything was fine for roughly 10,000 miles or so and they went bad. Replaced them and after that the car started going through o2 sensors. I have had the car retuned and it didn't help. I thought the part store sensors were junk so I tried gm and that didn't help any. Right now I can replace the sensors, clear the code and within 40 miles or so the light comes on and it throws the codes for the o2 sensors. The original o2's lasted awhile after the mods. i am totally lost on where to begin. I've been told to check my grounds so I'm going to try that. Any insite would be greatly apperciated. Besides the grounds i have know idea where to start. The car does have a cam and some head work and the last tune was done by a reputable shop. Please help.

Maybe, try the correct forum?/ Most likely to get more responses..
http://www.ls1tech.com/forums/advanced-engineering-tech/396223-what-forum-please-read-before-posting.html

what fuel are you using ? i hope it is not leaded fuel .

do you have cats or an off road pipe?

reason i ask is cuz i have been through this before, off road pipes and still running 02's that is, see your 02's hafta get up to around 600 degrees before they start generating voltage and without the cat there for some hold up the heat was going right past the sensors and not getting them warm enough, we let the car idle for half an hour and shot the pipes with a heat gun and they were only around 400 degrees. anyways it is possible for the exhaust to run too cool this is why alot of people delete 02 sensors with off road exhaust. you could try pulling the sensor out and looking at them if there is alot of black on them then your prolly runnin tooo cool down there, and if it interests you, you could also put the sensors in a vise or hold them with vise grips or what not and hold a torch on the business end and hook a multi meter onto the wires and watch for voltage, 450 mV is what you are looking for you will go up and down around that voltage as you heat and cool the sensor with the torch and dont be afraid to get it red hot a little it wont hurt it and you should also see the black crap come off the sensor should there be any on there. just an idea not sayin i guarantee this is your problem but it was mine and would up learnin sumthin cool onhow to test them in the process, scanners work also to test them but a torch is much cheaper and who doesn like playin with fire

Are these pre or post cat sensors? Do you have cat's?

With longtubes your best bet is to delete the rears anyways. Also look for any exhaust leaks. My exhaust y-pipe uses band clamps and they sometimes leak a little. Any leak like that could promote insufficient switching and throw a SES light. Like you said check/clean your grounds too. I replace mine every few years, but I only use AC Delco's.

the rear o2 sensors are only there for catalytic converter performance. if it is the rear o2 sensors that keep going on you, just rip them out buy some o2 simulators or get the pcm tuned. and your problem is solved.

Have you tried Bosch 13111's, I got those on my M6 and they seem to be doing a great job and it gets 26 mpg week in and week out. My A4 WS6 runs open-loop(no 02's), I don't have to worry about them but it get some super bad mpg.

reason i ask is cuz i have been through this before, off road pipes and still running 02's that is, see your 02's hafta get up to around 600 degrees before they start generating voltage and without the cat there for some hold up the heat was going right past the sensors and not getting them warm enough, we let the car idle for half an hour and shot the pipes with a heat gun and they were only around 400 degrees. anyways it is possible for the exhaust to run too cool this is why alot of people delete 02 sensors with off road exhaust. you could try pulling the sensor out and looking at them if there is alot of black on them then your prolly runnin tooo cool down there, and if it interests you, you could also put the sensors in a vise or hold them with vise grips or what not and hold a torch on the business end and hook a multi meter onto the wires and watch for voltage, 450 mV is what you are looking for you will go up and down around that voltage as you heat and cool the sensor with the torch and dont be afraid to get it red hot a little it wont hurt it and you should also see the black crap come off the sensor should there be any on there. just an idea not sayin i guarantee this is your problem but it was mine and would up learnin sumthin cool onhow to test them in the process, scanners work also to test them but a torch is much cheaper and who doesn like playin with fire

I'm thinking that my lack of exhaust temp is part of the problem. I can grab the collector within a few minutes of killing the car. I'm going to pull the 160 thermostat out and go to a 180 or 190. More than likely I'll go to a 190. I'm with you on the lack of back pressure not helping(with heat retention). I've got 3" duals with an x-pipe dumped before the rear. I think the thermostat and checking grounds are going to fix this problem.

Are these pre or post cat sensors? Do you have cat's?

With longtubes your best bet is to delete the rears anyways. Also look for any exhaust leaks. My exhaust y-pipe uses band clamps and they sometimes leak a little. Any leak like that could promote insufficient switching and throw a SES light. Like you said check/clean your grounds too. I replace mine every few years, but I only use AC Delco's.

It's my fronts. Killed the rears while getting it tuned. Never thought about leaks, good call. I got band clamps also so I'll double check that.

Have you tried Bosch 13111's, I got those on my M6 and they seem to be doing a great job and it gets 26 mpg week in and week out. My A4 WS6 runs open-loop(no 02's), I don't have to worry about them but it get some super bad mpg.

I believe I have along with factory and it didn't help.

Thanks for all the help guys. Right now I'm helping my buddy paint his IROC when it's done I'll try all this stuff and hope it works.

how bout you post some pics of that there IROC when your done with it i LOVE those cars :)

how bout you post some pics of that there IROC when your done with it i LOVE those cars :)

Can do.

twelver12, you solved the problem. I did the grounds and thermostat so one of them fixed it. The car is still getting painted and should be finished soon.

This is very good info, thanks twelver12. I'm going to try to change my fan settings to come on a later instead of sooner.