when you put lt's on the stock o2's dont heat up enough any longer and are not accurate at all. The vette o2's heat up to the proper temp when running LT's on the trucks

 

hmmm,which would cause it to run rich or just erratic?

 

My fuel trims, are all within 2% on the wideband and then going back to closed loop my fuel trims end up around 6-8% rich on the o2's. they do start switching slow as well (getting lazy as some call it), due to them not heating up enough.

 

both mine are throwing codes thats why i'm replacing em. They have close to 90k miles on em so can't hurt. Plus the longtubes are in effect.

 

hey is it bad to have your 02 sensors turned off with a computer from the dealer? because my truck was mis firing and i turned the 02s off and no more mis fire

 

To put it plain and simple the stock narrowband O2s dont like modded cars and trucks with longtubes especially if your O2s got some miles on them.

Some people claim that the vette rear O2s didnt make a difference but from what the majority of people say that I have gone to them from what I have read said that they did help quite a bit.

Their are quite a few guys out their they got sick and tired of getting the O2 sensor switching and heating fault codes and just decided to run open loop.

 

Also another big factor that people tend overlook sometimes is just because you aren't getting any fault codes set by the pcm for the o2s doesnt mean that they are working correctly and switching how they should.

It can be seen plain as day if you log the o2 mv in either hptuners or efilive in the chart display whether or not your 02s are switching like they should be.

I have personally seen in my own truck how "lazy" (not switching) the o2s were being and their were no codes or anything what so ever.

 

Please keep in mine that when looking at 02 sensor data that some scanners are slower than others. The Tech 2 will show 02 data change faster then my Aeroforce gauges can.

 

This is correct, some scanners have faster refresh rates than others. Even with a less powerful scanner, it should be very easy to detect a lazy O2 sensor though. Once an O2 sensor's cross counts become slow enough, the PCM will detect it and trip a code.

 

I used a rear o2 in my front left bung. I just switched the connector. No problems whatsoever. And I do believe that the rears have stronger heaters, so I would recommend putting both rears in your front