Generation III External Engine - SLP LM popping?

i just installed my slp lm catback myself, took it out for a lil test ride, and of course had to lay on the throttle. i love the sound, not too loud crusin, but oh man does it sound sweet wot... anyways... when i get back off the pedal i heard a loud back pressure pop/ back fire sound. tried it a couple more times and same thing every time. i figured it's just because of the "straight pipe" design, but it didn't even do that the 2 days i was riding around w/o a catback on my car. just curious if anyone else has this problem, or if anyone would have any idea how to fix that? thanks everyone, anything would be greatly appreciated.

I have the same sound, not sure if its back pressure or what but it only does it when the engine is cold. After 5 min of driving it wont do it anymore. When it is cold though it'll do it if you back off the gas when you hold it at semi-high rpm (or something like that) and it'll also do it when I push in the clutch when the rpms are climbing down.

that's normal. My Borla catback does it and so did my flowmaster before I tossed it out. I believe someone said that installing headers gets rid of it.....I don't know for sure.

that's normal. My Borla catback does it and so did my flowmaster before I tossed it out. I believe someone said that installing headers gets rid of it.....I don't know for sure.

It does, I just had headers installed last week and the popping is gone, but so is my resonator, they just ran 3in pipe from the ypipe to the LM exhaust. It sounds alot deeper and very nice!

I have the same sound, not sure if its back pressure or what but it only does it when the engine is cold. After 5 min of driving it wont do it anymore. When it is cold though it'll do it if you back off the gas when you hold it at semi-high rpm (or something like that) and it'll also do it when I push in the clutch when the rpms are climbing down.
Agreed! exactly like mine, until I put in a Moroso spiral flow, now all of that is gone

The popping when it is cold is from the air injection system. It will quit when it warms up or when you remove it.

I forgot to mention.....mine does it briefly every time I fill up with gas as I am shifting gears :(

mine does it briefly every time I fill up with gas as I am shifting gears

Yeah, it scares the crap outta the driver in my refueling truck :lol: