I went back to the track Monday last week and had a good time with the Civic, but it was clear there was still some kind of misfire or something going on. After struggling to change the throttle position sensor on the throttle body, I decided it was simpler to just buy a whole used throttle body than to try to fix the one I had. After installing it on the car, the check engine light was still on. The car felt OK, so I took it to the track as is.
I managed a best lap of 1:02.74 and the setup of the car felt right. I also took out one of our members' girlfriend for a few laps. She seemed to enjoy it. I feel that there is still some top-end power missing. Since I've eliminated the TPS issue, if there was one, I am thinking it's a spark/distributor issue. Also, there was clearly some kind of exhaust leak by the end of the evening. As a results, I dropped the car off at Pat's last Thursday so he could look into these issues. He immediately noticed that the header was cracked, but said not to worry, as he would weld it back up. As for the distributor, I brought him most of a used one and I hope he can replace whatever needs replacing.
He still has the car and I'm waiting to hear from him. Hopefully he can solve the engine issue quickly and I can be back on track Monday.
Here are some photos from last Monday. Thanks to JAG for the photos.