My car basically has no problems except that every once-in-a-while (btw one and five times a day if i drive for a while) right after i apply throttle after shifting to a higher gear (either 2nd, 3rd, or 4th usually) i sometimes hear a short "pop" in the muffler/exhaust....thats all that happens, nothing else as far as i know (like no fire out of the muffler or anything...but not sure)...is this backfiring? what could the problem be? i just had my timing belt replaced but it used to do it once in a while before that too...i have an apex'i n1 catback exhaust and a frankenstein motor (b17a1 '93 gs-r block with a b16a2 '99 Si head)...will this cause any near future problems or anything like that? thanks

 

do u have a cat? if u dont have a cat, that would happen sometimes.

 

What size is your pipping? I think your just hearing a echo from the engine. I use to hear that. Now i really backfire and shoot flames, trust me youll know when your backfiring because youll hear and feel it.

 

When I swapped in my LS, I had a MAP sensor problem, which caused it to run too rich. I also have an Apexi N1 (love it) and that badboy used to pop when I drove hard. I've also seen guys running chipped ECU's that run rich and they have the same issue.
So pretty-much, check and see if its running rich i guess.

I also have no cat.

 

lol good question about whether or not i have a cat...i havent had the car long so not really sure but i think its a full catback N1 so i think i do...and i dont feel the pop at all i just hear it quickly sometimes if i am a little slower than normal with the "clutch-up to gas down" process after shifting..and it rarely happens but at least once a day usually. sometimes its louder than usual but not often..worries me a little but i dont really know what to think about it

 

No i just had that exhaust setup too and I had no cat, and it did it all the time. I just changed to a world sport (i love it) and its gone. I have heard that w/ the n1 and no cat, it is common.

 

well what if i do have a cat and it does that once in a while...is that a problem??

 

I think your fine...mine does the same...just more often...mine sounds kinda of putter-like noise..but it pops when I shift but it never bugged me..Its been that way for awhile and I never had a issuse with the car...I think its just abit of back perssure or running rich..I dunno..I wouldn't worry about it

 

cool...also once in a while,i can haer it do a few really quiet versions of the pop noise in the rear when i just idling or driving slow in first and stuff like that...does any of this mean anything serious? sometimes when it happens after shifting its pretty noticeable from the inside since ppl in my car hear it too...bothers me still..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by just4747 &raquo;</TD></TR><TR><TD CLASS="quote">My car basically has no problems except that every once-in-a-while (btw one and five times a day if i drive for a while) right after i apply throttle after shifting to a higher gear (either 2nd, 3rd, or 4th usually) i sometimes hear a short "pop" in the muffler/exhaust....thats all that happens, nothing else as far as i know (like no fire out of the muffler or anything...but not sure)...is this backfiring? what could the problem be? i just had my timing belt replaced but it used to do it once in a while before that too...i have an apex'i n1 catback exhaust and a frankenstein motor (b17a1 '93 gs-r block with a b16a2 '99 Si head)...will this cause any near future problems or anything like that? thanks</TD></TR></TABLE>

well it calls backfire...yes you're right...ithink you engine is running rich with newer and larger piping....it's normal....once a while is normal better than runnign lean...

 

My EH has the same problem. I have a b18c1 with a universal apexi n1 on it with 2.5" piping. It only happens sometimes. But i don't notice my car burning rich since my bumper does not have any residue or black soot on the rear bumper. My friends 98 gsr did it once in a while too. He had the HKS hiper which is almost similar to the aepxi n1.

 

My car back fired all the time after I put my exhaust on. It was a stock DX engine too.
I don't think you need to be concerned about anything.

 

ya mine does it too and it putts like a bastard but I mean the thing is riding better than ever so don't worry about it man

 

yeah thats whay i meant besides the popping noise sumtimes after shifts....it also putts very little sometimes when cruisin slow in 1st or second...but barely

 

it also happens sometimes when u accelerate pretty far into the rpms in 2nd gear and then just release the gas completely...as it slows down kinda fast, you hear the puttering type noise a little bit in the exhaust quietly...sometimes

 

happens alot. i kno one of my spark plugs are getting fouled so it could be a factor
2.5 catless

 

mine backfirea alot...i have a 2.5 cat going into a 2.25 exhasust system...but i am runnning rich as helll..

 

same here super rich and lean in vtec

 

how can u tell i ur runnin lean?

 

I dont think its really a big deal. My car does it too with a catless 2.5 Skunk2 cat-back. You may want to try to unplug you batt. cables to reset your fuel maps. It may help, but IDK.

 

With stock exhuast, my car never had a "pop" sound. But recently, I noticed that my exhuast rusted off from the axle back. I took it out, and now I hear pops a few times a day.

 

trust me you will definately know if u got back fire...

lol i can cruise and decel while in gear and if i tip in the throttle just a hair ull just hear a loud pop. then my phone rings and its a friend callin me to tell me im shootin flames again

 

Its a problem because you could blow out your cat and o2 sensors. I would verify your distributor cap, plugs and wires too. Do you have tubular exhaust bolted to the head, and if so does it have a heat shield or wrapping?