Originally Posted by Tripintaz
Your reading comprehension score must have been on the low side. He has an OTS tune from TP. That map did not cause a big backfire due to poor tuning or timing. Most likely he hit boost cut or popped the TB hose.
Originally Posted by dsmtweaker
If his car backfired, he would not be driving home, as he would have destroyed many things. if it was after fire(which I believe is what you meant) then it would have been an exhaust pop(not under the hood) and would not throw a cell, as that happens post cat, where there are no more alarm sensors.
No, I meant backfire.... Ive herd and seen it happen on subarus. Most common on N/A subarus or EJ20 WRX's with TGV deletes and no tune for them, it will happen. If small enough it wont hurt, there are many other ways to get back fires on EFI engines. OP has AVCS and if the timing was not properly adjusted for many things that I really dont want to get into, it could have done that in the higher RPM that he had this happen at. Yes it would have to be pretty damn far off, but being it was E-tuned..... you never know what is going on. Remember, OP says "the car started slowing down then POP", all while at 60%-70% throttle. Sounds timing related to me. Further, op never said anything about the car running like $hit after it happened. Not having a intake related hose connected will cause engine stall, poor idle, and Zero boost. Where did op state any of that additional info!?!
OP, if youre car boosted fine after this happened, then it was something else. But you never stated it didnt boost after or didnt idle correctly. If you blew off a hose the car would have almost shut off and would be falling on its face when you gave it throttle after it happened. But you have yet to say this also occurred. This is WHY im left with saying it may have been a serious backfire and you may have been lucky it didnt cause major engine damage.