Check engine light, 5 fault codes
2004 RAV4 (68,000 miles)
The other day while pulling into a parking stall, the Check Engine Light, VSC TRAC, VSC OFF lights appeared simultaneously. It was running fine, as usual.
I pulled the fault codes with an OBDII reader:
P0300 Random/Multiple Cylinder Misfire Detected
P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0304 Cylinder 4 Misfire Detected
P0442 Evaporative Emission Control System Leak Detected (small leak)
A quick Google search revealed that P0442 might be a defective gas cap. So I unscrewed it once and put it back on.
Then, by coincidence, I checked the air filter. I forgot that I replaced it recently. Anyway, I noticed that the gasket on the air filter wasn't molded properly, it wants to slip off on the right side. Could this explain the "leak"?
I reset the fault codes, and wouldn't you know it, the faults disappeared! Everything looks good now.
Should I follow-up on this problem, or just forget about it?