The previous owner had the car dealer maintained, even oil changes,til 105,000 when he decided to change on his own, with seven quarts of oil, he heard a knock 60 miles later and was told to junk it. I saved the prestine car from certain death. After hearing what happened and hearing what sounds like a upper end tap passenger side and rough idle, with hesitation, and yes the tap is still there. I thought I could fix it. I have checked for voltage at the injectors and its the same as driver side.Where can I get a "noid" light. Im thinking timing issue also, I was told it has a chain and its not likely. Plugs are new, wow, only one plug available at 15.00 a piece. I noticed the coppression was a little low but figured it was due to wear. I thought it would be zero or a lot lower if valves were off time. Is there a way to check valve timing, it mentions valve timing as a possible problem in All Data's troubleshooting section.All Data also stated that valve timing was a moderatley common problem.And is it possible the engine is not trashed if it did go out of time? Would you recomend a leak down test? I did get misfire codes and somethig about bank sensor temp to low, I think thats the o2 sensor. I will get exact codes and numbers today. Thaks again in advance. Paul W