Robmac

Hi, I recently put an air filter and Mugen exhaust on the car, was on a long drive and it wouldn't go above 4k Rpm, so thinking it's an issue with maf or iacv. I've taken the filter back off, but still getting issues, thinking I might have to take exhaust back to stock. I'm led to believe the ECU on these is locked and de-tuned, so possibly not able to reprogram without replacing
Can anyone make sense of these numbers please? I'm not getting any eml come on and no codes showing.
Many thanks