I was looking for any hints on what this could be...I have a 96 SE with a JWT popcharger and an Apexi WS exhaust, and when I let off the gas, there will be a rumbly noise and sometimes it will have a small backfiring noise. the rumbling I can handle, but the backfiring isn't so great. I was thinking of adding another resonator to quiet things down a little (would a 350z/g35 resonator fit...I like the sound of their exhaust...I know I have a max and it won't sound quite like a 350z/g35) or is there anything anyone can think of that might be causing this? Thanks!

 

Finally a real mechanical post.

Backfiring is usually caused by bad timing. Is your check engine light on?

Also how many miles on your car? Your timing chain might have slack in it and have slipped a few teeth.

See if you can get some codes from the ECU. Let us know how many miles and if you've disabled any of the sensors when you modded the car

 

Mine both do it all the time. Another resonator will do the trick ...

 

My car does have high mileage...hit 182k yesterday. No CEL. Thanks for the tips...I'll look into that.

 

its called less muffling.....an OEM muffler usually hides all that noise.....

 

mine back fires when i let of to shift

 

i wish my car back fires, i would like to see it shoot flames.. sorry im a ricer lol

 

slipped a FEW teeth? then the engine wouldnt even start at all...and the valves would be done with

backfire is usually caused by a slightly rich air/fuel mixture.

 

I have the same problem. I guess that explains my poor gas mileage, less than 20mpg.

 

poor gas mileage can arise from many different factors, here are a list of things to check
-air filter
-fuel filter
-o2 sensors
-CELs
-knock sensor
-are you flooring it a lot?

there are more to check, but i dont know them all..but these are just some things to check out to find out why you might be experiencing not so great mileage..

 

for some strange reason this one sound more familiar.... .... lol

 

This happens from time to time when the engine is cold.