Please HELP! engine makes popping noise through exhaust

[Fender Defender]

My sr20det makes popping noises when I start it up like at idle. When I push the gas pedal on idle at every 300 to 500 rpms(random) itll make that noise a little. When I look at the motor everytime it pops it shakes the motor a little then it comes out through the exhaust manifold to the exhaust. Sounds like something igniting like popcorn popping lol. Then when I drive it and the car warms the the popping noise goes away from less to none. Then when I stay on idle for about a minute or 2 it starts making noise a little.
I changed the sparkplugs a few days ago the gapping was at .032. The old sparkplugs were kinda black and old. I was going to change the exhaust manifold gasket but I checked and it looked good. I retarded the timing a few days ago to make the sound go away a little and it didn't go away but it just lessenend it and the sound was a little less loud. It doesnt effect driving but it gets annoying and it scares me a little. no smoke or anything please help!!!

My setup
sr20det
stock t25
stock injectors
fmic
300zx maf
megan exhaust manifold
3 inch downpipe all the way back to 3 inch exhaust.
hks ssqv bov
walbro 255 fuel pump
apexi power fc with enthalpy's base map

[Fender Defender]

am I running too rich? or is it an exhaust leak? coilpacks? another info is when I got it in Inland empire at a high elevation it didn't make the popping noise but when we came down to oc it started doing that.

[Big Zee]

blown exhaust gasket either at your manifold ot on attached to the turbo.

[Fender Defender]

aight forsure good thing i bought a gasket already I'll change it this week and see how it goes. Thanks alot Big Zee for the headsup.

[240sxfamily]

leaky injector?

[Fender Defender]

hmm I don't think so cus I checked them and they were replaced not too long ago n the O rings are good too but I'll check em tommorow. N' thanks for the info

[Big Zee]

no worries mate, I had the same spounding problem and the gasket between the manifold and turbo was missing most of the side facing the firewall.

check it out, have the car running and see if you can notice any air movement in that area.

another thing is that your turbo nuts may have somehow backed off and your turbo is just hanging there ( which would be fixed with new locking plates and turbo nuts )
( this happened to a buddy of mine, but he wasn;t so lucky to get a chance to look, it just fell off haha)

[Fender Defender]

Hey Big Zee yeh the intake manifold gasket was leaking at the part that's attached to the motor. i just took those bolts off on the top so i can pry it loose but what else do I have to take off to take the intake manifold out? and thanks