I know I'm opening a very old thread but the original post looks like they still get on time to time. My question was did you end up rebuilding your engine or what did you find out? I'm currently fighting a similar thing on my ap1. My car smokes only at idle when the coolant temperature reaches about 200 degrees. If I start driving zero some etc. Car runs great no misfires no leaks. I've replace my valve guide seals. I'm running short on options at the moment. I got a leak down tester and a compression tester that I ordered and will be testing it later today. If those all pass I will try some Penngrade 10w40 oil and look into an air to oil cooler. So frustrating to have it run great and do this. I do have a catless setup and understand a catalytic converter does burn off extra crap but it shouldn't be smoking as much as it does. Any insight would be great! Thanks man