Quote Originally Posted by joecar View Post
Post logs.

Sounds like you're having to open throttle further due to lack of power.

Check MAF sensor to see if MAF sensor under-reporting, and clean it with MAF cleaner.

Check for the presence of misfires.

Check that cats are not clogged.

Check air filter.

Check that all spark plugs fire correctly.

Check that injectors do not leak.

Check rail pressure and check that FPR is not leaking internally.

Thanks Joe to for getting back to me. Will get logs after I get my laptop back. So far I have verified the MAF is accurate and clean. Built and insulated the charge tube and MAF to control somewhat IAT heat soaking and accuracy verified. No misfires on premium fuel in all throttle ranges. Do have an occasional on 87 octane. Replaced cats and whole exhaust last year. New larger air filter and sealed box with hood. Plugs look great with good color as do the domes. Last two injector leak down and rail pressure have not been checked yet. Running stock jeep pump in tank. Motor only had 20 or so miles on it. Fell off of a car carrier salvage yard told me. Funny thing is that it runs great, has great power and looking around on other Chevy and GM forums probably should be happy with what I am getting, but the exhaust is black and that bothers me. Black Bear took a stab at my tunes, which is stock for 2011 flex fuel, and thought it was incomplete combustion. That would make sense still if lugging this motor down to much is causing it to go into OL. I need to pay attention to this also more in the future. Have set MAP kpa to 85 per Robbi at MOTECHS request and AFM is off. These units are aerodynamic pigs so lugging them may be bad for efficiency? Thanks Again!