While driving home today suddenly the car started to run rough and had less power. Within a minute the check engine light came on. I was able to drive home. When I exit the car there's a faint rotten egg odor from the exhaust.
The ODB2 reader reported 3 codes: P0301, P0303, P0301. They mean cylinder 1 and 3 misfire.
I check the web and there are a dozen or so possible causes. Is there a way to coax more info out of the car so I can narrow down the problem?
For example, spark plugs could be a cause, but the chance of two spark plugs going bad at the same time seems low. On the other hand, car problems don't always follow logic, so I can't rule this out. Replacing spark plugs is a big hassle, so I don't want to do it unless necessary.
I found one bbs post say that if the knock sensor go bad, it could cause 1&3 or 2&4 cylinders to misfire. Is there a way to test this without buying a new knock sensor?