Ok well history first, My truck is turboed, it has been street tuned by wheatley, i had a some oil in the intake problems but i think they are fixed for now. I have ngk tr6 plugs. I my autotech gauge started showing random misfires and i would would randomly get the p0300 code. Im also having random time where my truck runs lean even when i have have it set on cruise control. Ive changed spark plugs, ive changed wires, ive cleaned MAF. Ive read what i could find and am not sure where to check next. Bad 02 sensors should give me rich conditions not lean. Havnt ran an injector cleaner, what would yall recommend?

 

an intake gasket leak, or exhaust leak near the O2 sensor will give you a false lean condition.

your 02 sensors will eventually go bad so after you find the root cause, i'd replace them

 

A bad O2 sensor will give you a false lean condition, I see it all the time. Just 2 weeks ago tdrumm was getting bank 2 lean codes and the truck was running like poo. I checked the data and found that the bank 2 O2 sensor wasn't going about .2 volts, with no intake or exhaust leaks. After a 5 mile ride the sensor was pinned at 0 volts. His problem was intermittent also. Replaced the O2 sensor and the truck immediately ran well and the O2 sensor was switching rapidly between .1 and .9 volts as it should...another happy customer

 

could an 02 sensor be bad without throwing any codes?

 

just re read your response... Im reading lean condition from my wideband not the stock 02's It will randomly go lean and studder a little i figured a bad o2 wil just read lean and add more fuel. I still have the rear o2's that i pulled before installing turbo, ill swap them in and see if it works..

 

you work for wheatley or you just using their sig for some reason?

 

Yes, an O2 sensor could be bad without throwing codes...sounds like you have an actual lean condition though, according to your wideband. As you mentioned, if an O2 sensor was reading lean, the PCM would richen the mixture to compensate. Unless of course, an O2 is reading rich, and the PCM is pulling fuel to compensate...it could go either way.

 

It still could be an exhaust leak though. It will suck in fresh air and make your wideband read lean too

 

My truck is tuned by wheatley, well my passenger side 02 sensor was loose, but the lean condition is still popping randomly... going to have to check for other small exhaust leaks...

 

IPguy,pm me your number please