I am having a problem where the car will start running rough and shuddering sorta.

i cant really describe it well but it does not seem to affect the power or the sound of the car from the outside but on the inside you can hear it and feel it in the floorboards next to the trans tunnel.

It has happened in the past but it went away 2-3 days after it started. i didn't change anything nor could i find anything. same now. I cant find any disconnected/loose wires or lines.

It sounds normal from outside the car and in the engine bay. it does however if you rev the engine to like 2k and let off pop in the exhaust, it only used to do that if i went to like 4 or 5k. it has a bit more stumble off idle, and sometimes it will idle at 750ish compared to its normal 500-550.

mabe im being to **** about this but its my only car and i want to fix it before it gets worse.

P.S. i just noticed that if i flip the throttle when im over top the engine it seems to make a pop from the drivers rear. kinda backfire sounding but quieter and down low and to the back.

 

Sounds like it's excessively rich. Dying injector(s) possibly.