backfiring above 5,500 RPM

[mstng4point6gt]

recetly my car started to backfire when i shift above 5,500 rmp's. it doesnt happen all the time, it has only happened 4 times. Any idea's would be a great help. Thanks

 

[fastangboi]

What year is yours? My buddy had a 97 gt that did the same thing. It had an O/R H pipe and Flowmasters. i always thought it was just because of the waste spark style ignition. He had turn downs and we used to drive by peple and watch it light up as he power shifted. good times

 

[DeVus1]

Sounds like there is too much back pressure. If you go above 5500rpm, dont let completely off the gas immediately.