Popping from exhaust.

[blue46gt]

Hey guys. I have my car stored for the winter and I went out to start it up and when I reved it up it pops when I let off the gas. I have a mac o/r h-pipe and flowmasters with dumps and outlets out the rear. Never had this problem before. I was thinking maybe it was cold air getting sucked into the dumbs. But not sure. Maybe I have an exhaust leak somewhere. What do you all think? Thanks.

 

[Roger_4.6_96]

No cats to burn up your leftover fuel. So your fuel is being dumped into your exhaust and ignited in your mufflers.

So you probally had fuel in your mufflers and it ignited

 

[BMan5150]

No cats to burn up your leftover fuel. So your fuel is being dumped into your exhaust and ignited in your mufflers.

So you probally had fuel in your mufflers and it ignited

Yup. When you first start your car, it runs a very rich mixture. The colder the weather, the richer the mixture. That's extra gasoline shooting down your manifolds into your h-pipe and igniting. My set-up does the same thing when cold if I rev it - something I never do anymore. If I want to rev up the engine, it's got to be fully warmed up.

 

[blue46gt]

Thanks guys!! I would've never thought of that.

 

[steeda_gt_99]

Also be sure to check your cold air intake because if it has came lose somewhere then that can cause the noise you described after lifting the accelerator pedal.

 

[Darkhorse845]

No cats to burn up your leftover fuel. So your fuel is being dumped into your exhaust and ignited in your mufflers.

So you probally had fuel in your mufflers and it ignited

Bingo!

 

[C-dub]

Also be sure to check your cold air intake because if it has came lose somewhere then that can cause the noise you described after lifting the accelerator pedal.

i get the popping when lifting off the pedal, but the c/a is tight can this still be unburnd gas? if so whats the fix? running a 03 mach w/ bassani mids, x,cat and a k&n cold air.
thanks c-dub

 

[01MachGT]

mustangs just tend to pop some, especially if you don't have cats

 

[C-dub]

mustangs just tend to pop some, especially if you don't have cats

got the cats, just the bassani high flow metals. will the popping hurt anything? realy think i sounds crappy, like the car is out of tune or something?(custom dyno tuned installed)
c-dub