Blood

I have an 07 gt/cs and its misfiring when I really get on it in 1st and 2nd gear. I think it is atleast.

It will make a really loud backfiring noise and only does it sometimes.

Anyone got any cures to this? I dont think it could be the plugs. Check engine light came on and checked for vacuum leaks, found one fixed it, and it still does it....

So anything could help me.

Nuke

What's the code? My first thought is an intake leak but it could be many things.

ReaperStang06GT

Is this when your car is still warming up or possibly letting off the gas? Also, what kind of exhaust set up do you have? I know I get this kind of sound as well when it's warming up or just letting off with my SLP loudmouths.

moochman4life

1. Do you have a tuner or other device that will allow you to check for a thrown code? If it's misfiring, then it will tell you which bank. Also, if it's misfiring, then it probably has something to do with a plug.

2. When you say you found a vacuum leak, where/what was it?

I've been through the popping noise/backfiring thing for the last few months. First, it was water that got into a coil-on plug (this threw a code). Second, two of my plugs - literally - unscrewed themselves causing a vacuum leak (this didn't throw a code).

Blood

Its when I am really getting on it in first and second and right when I let off the gas it pops. Its actually my cousins car so Idk all about the damn thing I have an 04 mach 1.

But the vacuum leak was at the intercooler intake. The tube that goes from the intercooler to the intake. And he has it sct tuned but the guy he bought it from never gave the tuner up.