exhaust popping

[tylermartindc]

so i have a 3 inch ss turboback exhaust, it had no cat and it ran like stink, now i had to put a cat on and under load at low rpm when i punch it, the car stutters and pops and then once i hit abot 4500 rpm it goes away. happend the day i put the cat on and ever since. it will boost to about 12-14psi then wont go past 12 after it stops popping. anyone have a remedy for fixing this without simply putting the straight pipe back on? im trying to stay legal

 

[somdturbo]

Is this a used or new cat?

 

[JayRolla]

Not having a cat would not cause the car to run poorly. I think the cat has nothing to do with the problem. All you did was free up airflow and it should not cause a problem.

 

[RiceKiller_TSi]

Sounds like your're running really rich.
The popping is caused by the unburned fuel pooling up in the cat and then detonating from the hot exhaust. That cat may be clogged up causing this problem. If not, then check your a/f.

 

[JayRolla]

I used to get a big pop at high RPM's and my car would let out a ball of fire. Turned out to be bad plug wires causing a miss fire.

 

[tylermartindc]

sorry just to clarify, when it had no cat it ran awsome , really fast. then after the install it started doing this weird popping thing. it was a brand new cat, my mechanic never specified what brand or anything he jsut said it was real hard to find a cat that was 3 inch in and out. "rice killer " you sound the most right to me, what should i do ? maybe try getting a new cat or what ? pretty much open to anything.
thanks

 

[thilaksharma]

pop with black smoke is for sure rich
i used to have a pop when i dint recirculate my bov
if u have pop with nice flames hahaha then ## confirmed to be rich
just recheck ## fueling , plugs , cables

 

[VicBoost]

My car popped when i floor it sometimes. I fixed this by getting new NGK spark plugs and now it runs awesome!!!

 

[nightspeed87]

Sounds like your're running really rich.
The popping is caused by the unburned fuel pooling up in the cat and then detonating from the hot exhaust. That cat may be clogged up causing this problem. If not, then check your a/f.

That makes sense because my car would pop a lot while its revving down but after the car wass fully warmed up it wouldnt pop anymore, only in the warm up process I guess you could say, and I recal reading something about the 02 sensor wont read properly until in operating condition and therefore it will just read rich when your still in the warm up phase, * which is when mines pops a lot....
I only have 2.5 all the way back and a muffler, and no cat and stock down pipe thats just ported out a little as of right now.

 

[RiceKiller_TSi]

sorry just to clarify, when it had no cat it ran awsome , really fast. then after the install it started doing this weird popping thing. it was a brand new cat, my mechanic never specified what brand or anything he jsut said it was real hard to find a cat that was 3 inch in and out. "rice killer " you sound the most right to me, what should i do ? maybe try getting a new cat or what ? pretty much open to anything.
thanks

If your car is tuned well, (that is good plugs, wires, unclogged injectors, good spark and so on) then the problem is most likely a bad catalytic converter. If its new, you shouldn't have any problems, but if its used then, it may have rust inside it or be clogged up with crud. Simply put that popping is caused by running rich one way or another.

 

[tylermartindc]

how can i clean my injectors ? i thought i could use one of those additives you put in the gas tank. u think that would do the trick ? any recomendations? im going to get some new plugs and wires, fuel filter, and look into a new high flow cat.
thanks guys.