Quote (OldAndyAndTheSea @ Jan 3 2013 09:21am)
Question: It may sound stupid, but are you sure you are leaning out? Do you have a Wideband to confirm? If so what were your 02's?
Has anything else been changed? Injectors? Raised Boost? FMU? What does his intake look like? Been ported? How are the runners? Things like that matter big time.
Exhaust design CAN influence a lean condition, but before I send you down the wrong Rabbit hole, I'd like to know a little more about the vehicle.
You can hear pinging and the engine is letting off and jerking hard, we hooked up my old narrow band it goes lean after 4000 rpm at 80% throttle. The fuel mods include a 55 psi fuel pressure regulator, Bosch big green injectors( 550 cc ).. the tune is meant to be useable with the stock turbo and fuel pump... the other requirement from the tuner is a 3'' down pipe but the one he has is a 2.5'' down pipe but its like i said made very poorly and i can see the flow being totally moshed up.
this is a correct down pipe for the tune his is a pile of shit like i kinda drew in the picture the cat is located right off the turbo almost and its at a 90 degree angle, so the EGT's are getting way beyond normal temp and causing the fuel to pre ignite that's my idea.