Diagnostic help needed! Hot film MAF and low oxygen adaptation.

[Danimal]

Had an about an hour to some more diagnostic work. Jacked up both sides of the car and banged along the exhaust from heard to tail pipe on both sides. It’s definitely the drivers side of the muffler, probably the top mount.

I took it on a 30 minute highway ride to run cycle the battery/fluids since it’s been sitting for awhile. No noise on start up, but some exhaust rattle at idle. Still no check engine lights, but I didn’t really push it.

[Danimal]

Another update. I've taken the car on 5-6 runs and the check engine light hasn't come back. However, I'm experiencing a slightly rough idle and slight hesitation around 4k (almost feels like power surges). Looking around I found someone on the pelican forums with the same issues.

https://forums.pelicanparts.com/boxster-cayman-forum/600891-bought-durametric-but-i-need-help-understanding-numbers.html

I checked my fuel trims and they are almost identical to what this person had. The fix for them was a new MAF. I'm going to order one and give it a shot.

Note: I also did the oil cap test. I took it off with the car idling. I was able to remove it no problem and the car immediately began to run poorly....so I think the crankcase vacuum is okay.

[Danimal]

Update: new Bosch MAF sensor is in and I reset the fuel trims. I’ve taken it on 4-5 medium trips and the fuel trims are now FRA 1.05 and RKAT -0.42 for bank 1 and FRA 1.02 and RKAT -0.42 for bank 2. A lot better than the 1.28 and -3 I had before.

I need a few more spirited drives before I declare victory. But it feels pretty nice!