Ok, my friend has an 01 Z24 2.4... Check engine light was on for Cam Sesnor, so I replaced it, no fix. Symptoms... Rough Idle, will not rev above say 3k rpms, sucking too much air thru the intake, and when you rev it up, the valves chatter like crazy. Can't drive the car down the road, if you lightly accelerate it will go, but to try and go any faster than about 10 or 15, the car dies.
Oh, not to mention the Trac Off lite stays on constantly, and the check engine light and service lights stay on. I'll have to run the codes again to see what all it shows..