Guys, after truning off my truck if I be quiet I can hear a noticeable deep POP or backfire I guess you could say. Why or what is causing this. I have a new Edelbrock performer carb part number 1406 w/electric choke. I had this same pop problem wiht my old stock Holley 4 brl btu I think all we did was secure a plug wire that was off. Could this even cause this POP?? Help me out please.!

Mooseykat

Backfires are caused by a rich condition in the exhaust finally getting the right fuel/air/temp combination to burn. A loose plug wire will richen the exhaust since the fuel to that cylinder isn't burning. The heat from the cat can set it off after the engine is off since there's no more outflow and air can leak in any little holes in the pipes or muffler, or in thru the tailpipe.

Steve
83 Custom w/95 4.9L EFI, 78 NP435, 83 NP208, 83 D44IFS 3.07, 87 Ford 8.8ABS 3.08, Michelin LTX AT 31x10.50R15