Fastloader

Have a 2010 mustang shelby gt 500, I have stock headers and a Magnaflow catback exhaust. 2.9 Whipple Supercharger with smaller pulley and tuned with 123mm JLT Forced Air Intake (the big cone lol). I am not the handiest and I am learning quickly about this amazing machine. I added some octane boast and an injector cleaner additive. I hit the rev limiter and I had a big back fire with black smoke. After the the car game me a P0104 MAF air sensor problem and the car was also miss firing. The spark plugs were all changed and now I have constant backfire on the downshift or if I rev high and let off the gas the car will backfire on the deceleration. Dasilva Racing said I have a small exhaust leak on the drivers side header, but it is stock and they cannot believe that it is leaking.

They re-tuned it and I am still getting a MAF sensor error p0104 and I am told that the backfire is normal. Sorry about the long winded question but would sea foam or installing new headers solve this problem? I am thinking the exhaust leak is causing the backfire. I am putting 94 octane fuel in and it is tuned for it.

Wondering if I put in 93,or 92 octane and that would stop the back firing because of the higher temperature of combustion?? I am not sure what to do.

The header could be replaced for $500 but while they have it apart might as well replace with a better header. The back fire sounds like it is coming from under the car.


Thanks in advance.

FrostByte

So what your actually saying is you put reg gas in, then tried octane boost AND injector cleaner & then revved the **** outta it? oy vey

Pull the plugs & check for detonation.

Stop putting stupid **** in & just use the 83 or 94 that your supposed to w/ the tune. Octane boost only will slightly increase octane of gas.

Why would you need Seafoam? The highr octane fuels run cleaner & have all the cleaning agents you need.

STEP AWAY FROM THE AUTOZONE COUNTER.

Daehawk

Sounds like you should just give me the car since you don't understand it. I will baby it and drive it responsibly.