[Axio]

My car has been occasionally experiencing what I believe is a backfire when the clutch is depressed changing gears. This isn't the slight muffled popping noise i noticed when i got my exhaust, it actually sounds like a cap gun. I feel like uncle buck. I was thinking it could be the NGK plugs not completely burning the fuel and the gases combusting in the exhaust. Maybe I should go back to the motorcraft. I have headers, y-pipe, and dual exhaust. I have the stock cat on. Suggestions of what to do or possible leads. I don't expect the slight poping to go away, all research points its a common thing, but the occasional cap gun sound doesn't coordinate to anything I've seen in the archive. Thanks

 

[Guest]

Do you have access to a code reader? If you do find out your air/fuel and timing. To tell you the truth it baffles me why you would be backfiring with the few mods you have ( especially not having any fuel upgrades).

Not sure that helped at all but.....good luck!

 

[DanG]

Experience on this board has told me to pretty much point the finger at your Pro-flow. The calibrations on those things appear to have more problems than they're worth. I recommend going back to the stock MAF. I don't recommend MAF upgrades in any way, shape, or form unless you're running serious F/I and are actually getting the "MAF signal beyond max high" CEL code. The stock MAF is not a bottleneck to even my 3L hybrid, especially with such a convoluted (by design, though!) intake system, and small throttle body. Even the SVT TB...

Naynay- I'm surprised at you- "Not having any fuel upgrades?" What is the MAF then? Its calibration DIRECTLY affects the A/F ratios that the EEC-V tries to put out. :shrug:

 

[mcon99]

My car has done this since I upgraded my exhaust and gutted my precats. I've heard the theory chopped around that this kind of setup creates a bit too much flow in the exhaust close to the engine, which causes some of the unburnt a/f mixture to be pulled down the exhaust a bit before igniting.

I've never found it to be that loud or annoying... and anyways, if you keep on the gas pedal it doesn't happen

 

[B3NN3TT]

Curious suggestion, mcon99. I'm planning on upgrading my exhaust to complement my gutted precats this spring.

How would one go about alleviating this?

 

[Guest]

To some since it is a fuel upgrade....i guess. So i guess a chip would be considered one also. My point since your making me spell it out is injectors or pressure regulator.

thanks for pointing that out:stupid:

 

[NascarSigEp]

Axio, my car has done that for the last 2yrs. When you free up the exhaust you will get that due to even a "SLIGHT" loss in back pressure. This does not harm your vehicle in any way. If you want the "pop" to go away, get a more restrictive exhaust system. Hell, mine sounds like a friggin shotgun sometimes.

 

[Axio]

Originally posted by: NascarSigEp
Axio, my car has done that for the last 2yrs. When you free up the exhaust you will get that due to even a "SLIGHT" loss in back pressure. This does not harm your vehicle in any way. If you want the "pop" to go away, get a more restrictive exhaust system. Hell, mine sounds like a friggin shotgun sometimes.

haha, yeah, my sounds like a shotgun too when i "get on it".


Will this backfiring get worse when I install my high flow cat sunday and lose even more back pressure?

 

[NascarSigEp]

It might only become a louder "pop" when you do that. It more than likely won't do it more often, just be louder. When I gutted my precats it got louder. Again, no harm. You just need to have some back pressure.