A few months ago my R32 GTS-t developed a problem that suggested it was being starved of fuel - in other words as soon as I tried to accelerate, it lost power.
I replaced the fuel filter without fixing the problem. My mechanic had a look at it and decided it was electrical so off to the auto-electrician who diagnosed a faulty AFM and a $500+ quote to fit a reconditioned one. I looked at our forum and found a post which suggested removing the AFM, cleaning it thoroughly with brake cleaner (non-residual) and resoldering the contacts in the body of the AFM. I'm sorry but I didn't photograph the steps involved but it worked! Save yourself some moolah and give this a go - no problems since!