SR20DET Rough Idle/Misfire/knocking noise.

[gmorcos37]

Hello all,

I'm having some problems with my SR20DET, mostly stock, just has a FMIC, and 3" catless exhaust.

The problem is that I'm having a slight knocking noise and rough idle. Also when it is revved up a bit, I can feel the motor misfiring as it shakes pretty violently. It seems like it is pretty consistent but random. It can occur once every couple seconds or like 3 times every couple seconds. Beside that, car drives fine, boosts fine @7/8 PSI and feels strong, with no real other apparent problems.

Something interesting I noticed is when I put my dirty air filter on, AFRs are about 16-17 at idle but when I take off the air filter I am getting a AFR of 13-15 at idle. But while cruising is stays pretty close to 14.5 and goes to 11.6ish at WOT near redline.

I checked compression and it was 150PSI across all cylinders. Got some new spark plugs as well but no difference.

No engine codes either.

Any help is appreciated!
Here is the video of the noise.

SR20DET Knocking noise: http://youtu.be/08L5Lu63z-8