Backfiring?

[Black Sun 5.0]

I was driving the other day when I noticed that the car backfired, or at leat there was a loud pop from within the exhaust pipe. What causes this? New engine, plugs, cap, rotor, ign. module, coil, X=pipe w/cats.

 

[HISSIN50]

it depends when it happened, etc. often a vac leak or leanness can cause popping.

good luck.

 

[04sleeper]

I second for checking for a vacuum leak.