I have an 03' Type S with 60k... Intake, Headers, Exhaust (No Cat. but I have had it "tricked" so the CEL stays off.) I don't beat the car up, pretty much normal driving conditions besides the usual race.

My Check Engine Light came on the other day and the car started to run like ****... When I press the clutch in/put it in neutral and the RPM's drop, they drop to just under 500 and the car almost stalls. It runs rough at idle but doesn't feel like a misfire. The car usually smells like exhaust but since the CEL its much worse. What the hell is wrong with my car??

I did have a problem like this in the past but it only lasted a day or two... I ran the codes and it said (cat. below threshold) or something like that. That usually comes on because of the no cat but goes away and doesn't run like ****... I put new spark plugs in a month ago too...

HELP HELP HELP!