Exhaust backfiring

[GrdLock]

I'm just curious... what exactly causes backfiring on exhaust? And is there any solution to getting rid of it? With my cutout, if I quickly let off the gas at WOT, I'll get a pop or two occasionally. I'm sure there's nothing I can do about it except close the cutout (which I'm NOT doing, I love the sound! :D ), but I'm just curious what exactly causes it...

[jrcamaro96]

I belive its the A/F ratio adjusting and thats what causes the pops. I have this problem also so i'd like to hear some suggestions on a cure also.

JR

[TrikdOuTbyrd]

im thinking that as your at WOT and let off the gas, you get pressure pockets in the pipe with high and low pressure areas and as the gasses are exiting the pipe you have no muffler to regulate or suppress these pressure changes/bursts, so instead you hear a popping as they exit the cutout......what do you think?

this is my theory, but if anyone has an exact answer i'd love to hear it

[JinX]

It really depends. I had a case where my car started backfiring real bad, especially on acfceleration, turned out to be a loose spark plug wire. Replaced the wire after realizing the clip was no good, and it never did it again. basically the backfire is the cylinder misfiring.
-JinX

[97CamaroV6]

I have this problem also, I took it in to a muffler shop and they thought the sound could be a broken baffle inside the muffler. The mechanic told me it all looks okay from the outside so unless it bothers me a lot don't do anything. Who knows if he is right but the only way to fix that is to buy a new muffler (so he says).

[John_D.]

When I run the full-open plate in my Borla, it pops a bunch on decel. With the fully-closed block-off plate it doesn't pop at all.

Engines tend to run rich on decel, and if you cut-out before the cat finishes burning everything, you probably are going to get some minor backfiring from going rich.

I read somewhere just a day or two ago, that the pcm will even cut the fuel completely off on a hard deceleration in some cases, to eliminate the rich condition. Probably takes it a bit to kick in though.

[ June 05, 2002: Message edited by: John_D. ]</p>

[Dojo2000]

I get that pop/rattle only when I am leaving my neighborhood up our steep hill when the engine is cold. I got it more frequently when I had the stock Y87 muffler on than I do now with my Ravin. I have to pull out onto the hill so I usually give it a lot of gas to get up it, then when I let off the gas it pops/rattles.

Now if he's talking about the nice rumble you get after you rev the engine/decelerate, you want that :D I think TrikdOuTbyrd pretty much right. You will know whether is a backfire(POP) or rumble(putt-putt-putt) Just my 2 cents

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