Having one MAFerf***er of a problem (No MAF works?!)

[Speed_Demon]

So a friend of mine owns a MK4 Golf GTI, that once fitted with a decent aftermarket air intake started to run horribly rich and idle erratically. Definitely seemed to be a little down on power.

No problem, must have knocked the MAF when installing the air intake. Whip it out and let the car run on it's last 'good' settings, all is good. Pick up a new MAF, put it in, exact same problem returns.

What is the problem likely to be? The only thing that occurs to me is the ECU, but that doesn't make sense?

Thanks.

[daveparry]

Take the aftermarket stuff off replace all original stuff and see if it still happens, probably just a coincidence putting new stuff on!