I have an update, I've been hoping to review a scan before posting but my cable stopped working so I have another diagnosis to do!

I brought it to my mechanic, they confirmed the IAC was bad. SPR performance service has been great during this process, and they sent me a replacement valve, as well as tuning up the TBI.

The mechanic installed the IAC and confirmed that fixed it.

When I picked it up, it still had a miss, and as it warmed up and I got onto the freeway it got a lot worse. So much for paying them to help with diagnosis!

I discovered a youtuber, ScannerDanner, who teaches auto diagnosis. I watched a bunch of his videos, and worked though his basic evaluations for a miss. I diagnosed a bad spark plug wire on cylinder #5, which was also the spark plug that looked the worst. Now I know that's another sign I should pay closer attention to.

Fixing that had a really big impact on the performance. That was last Sunday, and I drove it 60 miles that day. I still felt a little something going on, but it's driveable now. I also am using the stock chip program, the shifting is much smoother. I'm curious to see how my mileage and my acceleration performance will compare.

Once I fix my cable I'll take some more logs and ask the group here what they think about the timing.

I will also look around to see what I can find for a test procedure for the ignition module. I'm disappointed in the AC delco performance spark plug wires, they don't grab onto the end of the spark plug very well. They have a lifetime guarantee, I plan to visit the dealer today with the one bad wire and see what they do for me.