Well, I bought this car used last year and for about a month it was running wonderfully. All of a sudden, the Check Engine light comes on and I hook up to the OBD to pull some codes. Not surprising it's one of the O2 sensors. I replace it and the light goes away. About 2 weeks pass and then one morning, I can't get the car to turn on. I tried for about 2 minutes until it finally turned on. I figure it may be an electrical problem. I check the ground cables and have the battery tested. Every checks out ok. I move on to replace the air filter (although, the one in there was fairly new.) I installed a new fuel filter, fuel pressure regulator, spark plugs, wireset. It's still a pain in the ass to turn on! No codes come up, fuel pressure is normal. I have no idea what to do! Any ideas?