Whenever my B16 hits around 7500 it starts to "pop", it almost sounds like it's fouling out plugs, but it's not.

It was running very rich due to:

Bad TPS (which I fixed)
My dumbass messed up on a few vacuum lines (thanks RioNinja, I fixed it)
And I am only running one O2 sensor (2 ecu lines spliced into one sensor... i think if i buy a 4-wire heated O2 sensor, i should be OK)

I am also running the stock CRX Si exhaust, and I KNOW my cat has gone to ****. It sounds like it's backfiring in the cat.... and it rattles like hell from the front of the cat (it's most likely broken inside on the front). I've also blown the exhaust out behing the cat twice (c'mon, i was broke, i just ordered an exhaust ) so i had to weld that up. I'm pretty sure the cat is clogged up pretty good too.....

I was also thinking it COULD be a distributor or timing problem, but I'm really hoping it's not.

Anyways, whenever I hit 7500 its like waaaaaaaaaaaaa bababababblaaaahhhhh and kinda sputters and dies off. Every gear... also, it has a tendency to "pop" (in the exhaust, i can hear it) every onc ein a while at certain RPMs.....

I figure it's an exhaust problem... I mean, the car REAKS like exhaust fumes.... but I do smell gas too.... but I just wanted some opinions from you guys... thanks.

89 CRX Si
JDM B16a
AEM CAI
DC Sports SS 4-1

If that helps at all..... lol Not a good idea for a stock exhaust to try to take all that pressure from a 4-1 and CAI eh?

 

A clogged cat will kill you. So fix that. Are you still running a stock fuel pump?

 

Yeah.... I also thought that may be a problem....... fuel delivery @ 8000 rpms is pretty crucial... I'm 99% positive it's the cat, but just wanted to hear what you guys think... thanks man

 

da6poweredef got a point. you said you check the dist. but did you check the cap and rotors? is your car misfiring??

 

Unfortuately, I didn't change the cap and rotor when I swapped it in... now I'm thinking it may have been a good idea, while I had the $$$. But I'm thinking it wouldn't be a bad idea to do anyway... it's not alot of $$, easy to do, and can only help my cars' performance...

'90 Integra is where I get the parts from right? Non-ODB.... pretty sure that sound sright.

 

umm i'm not sure exactly what you're talking about sputter? does it make some kind of nose like ZzzzZZzZz or something.... if yeah check your mounts, see if their rip or something. also do you have any engine codes???

 

No, its definitely an exhaust, ignition, or fuel problem. It either feels as if there is too much backpressure or as if the fuel delivery is insufficient.... it kinda "putts" or chokes. ALmost like a rev limeter (but it's not)

No ECU codes, which is why I am thinking it's due to too much backpressure from a clogged cat....... any ignition or fue problems would probably be accompanied by a code.......

 

Cap and rotor are pretty cheap. I'd do that, and then hollow out the cat. If it still sputters, try using a dohc VTEC fuel pump (I use a 95 GSR), and see if that doesn't cure it. Mine didn't sputter, but it definitely pooped out a bit from 7-8k until I put the bigger pump in.

 

If your cat is old, replace it. I've heard of cars losing TONS of power with an old cat. Is yours original?

 

haha yeah, 12 years new

so i kinda think that may be it...