Tom, how the hell is an "uprated" (read "shit at filtering") panel filter going to reduce heatsoak? Where do you get this stuff from? But yeah, try unplugging the maf, if performance improves or stays the same, you've found your culprit.
As already said, bin the chip and give her a good service, always improves things. IMO the best air filter for these is a genuine pug one, after seeing some test results on the subject.
As already said, bin the chip and give her a good service, always improves things. IMO the best air filter for these is a genuine pug one, after seeing some test results on the subject.