I'm really not sure where to start. The car is in limp mode for the first start, but if I shut it off and turn it on again then limp mode goes away and it drives great. I really dont understand!

I've done a ton of research and nothing seems to really give me a clear understanding on where to go from here.
The car has been sitting for about 8 months. In those 8 months ive driven it about 5 times, all 5 times were amazing. The 6th time it went into limp and it's been like that for a few months now. It arrive in the US in January 2024 with an empty tank, I filled it with 93 octane and some premix, and I've only used half of that tank since then so the gas is old. Idk if that bit of info is relevant.

I've changed the spark plugs and wires, fuel filter, and drained the coolant and replenished. That's it.

The car is a 97 Type RS with 17,000 original miles on it (26,000 km). Original engine and trans. Knight Sports ECU, Knight Sports intercooler, Autoexe Exhaust, and coilovers.

 

welcome to the board.

the likely culprit is the MOP ... code 26.