Had a scare Wednesday. Rough running, CEL, had it towed to my parents' house and the family friend/mechanic read the DTC as cyl4 misfire. He suspected either hydrolock (due to my intake) or destroyed piston rings ("due to high revs - you autocross, right?" (eek2)).
I had to get back to class (luckily my family always has an extra car for some reason - I got dad's 2nd gen Protege), but I got a call last night saying that it had passed a compression test and he was going to try swapping the two coils. I had assumed that the guy who works on cars for a living would have started out by checking the ignition system when the ECM indicated misfiring, but apparently not. Swapped the coils and the misfire moved to cyl2; replaced the coil and the car runs good as new. The guy just about gave me a heart attack thinking I'd need a rebuild. I've never been so relieved to have a bad coil.