I have a 1995 Subaru Impresza 2.2 litre 4WD which has had its check engine light on for some time. The only real noticeably symptom was an occasional hard start. This was completely random, but it seemed that during the hot months it was more frequent. I finally took it into the shop and it turns out its a fairly easy fix. There are 2 bad sensors; the coolant temp sensor and the oil pressure sensor. My mechanic is fixing both for around $60, labor and parts. I am also getting a tune up to clean out the throttle body, etc. My question is actually related to the hard start however. Does anyone know if either of those sensors were causing the hard starting? One other thing that happened rarely was surging. If I was at a light idiling, it would jump forward at times and the rpms would also leap. I didn't know that this would be caused my the coolant temp or oil pressure sensors. I was convinced it was the MAF, but thats fine.
I just hope this solves the problem. Any help or comments are appreciated!