The shop manual has a helpful troubleshooting table at the front of the engine section - take a look at that. I would put a screen shot here but I have the 93/94 manual. Have you done a post head gasket compression or leak down test?
Possible vacuum leaks are a good suggestion.
Since MAF is...
OK, starting to get excited!
Question for the ride; maybe a little late to ask, but just occurred to me. What radio format/standard do you usually use?
The LHD is the same just mirror image. Install is a reach, but not too bad. @Outsane has a YouTube video of it.
Though I wonder if the air intake is a mirror image also and needs a mirror imagine of the filter, too
I installed the SolveFunction filter this past week. Haven’t tested it much yet, but excited to not have to keep the car on recirculate all the time to keep dust out.
Thanks! Yes, they are the 10 degree angle. When I ordered, full or partial diamond plate were the only plate options. I think @white-knuckleoffroad has since replaced the diamond plate options with the dimpled.