So I'm out of ideas, I have a popping noise when I cold start it and idles at 1800 rpms... Ex: pop *5sec later* pop) and almost every time I decelerate and/or change gears... It's getting extremely annoying and idk I checked vacuum leaks... I don't think I have vacuum leak because Idle is fine it's steady.... May it be exhaust leak I just don't know any ideas?.??

I do have a video I can email... It's me at idle revving

 

What car are we talking about here info helps. A 1.8k idle at start up is not unusal as long as it goes down. first thing that comes to mind is backfiring(when you deacelerate/change gears) could be running rich my 94 GSR crackles/pops when i deacelerate. PM me and i'll give you my e-mail tho it would help if you could upload it to you tube.

 

It's a stock b20z2 with ls tranny all that's done to it is no p/s or cruise control intake and full exhaust system, and I'll pm you I would upload it to YouTube but I'm on a cell

 

Any CEL's?

Video would be helpful. Sounds like the normal backfire/crackling that you get under deceleration after you put an aftermarket exhaust on. Not sure about the backfire at idle though, that's not normal.

 

No CEL at all put the motor in November and didn't get CEL once