Thanks for the reply, I checked the codes once the CEL came on and it came up with a code 11, which reads "Timing belt skipped 1 tooth or more from initial learned value, Intermittent loss of either camshaft or crankshaft position sensor, No crank reference signal detected during engine cranking". I guessed it was the crankshaft sensor based on the symptoms, and because it seems that oil leaks tend to kill them(of course I have a slight oil leak), but I'll look into the camshaft sensor.

How hard is the camshaft sensor to replace? If it's easier and/or cheaper, I may start with it first and see if that does it. Where is it located on the motor?

Thanks!
Adam