went to revo today told him issue he just scratched his head. my car has started holding back on boost and kind of juddering. He said buy a new air mass meter and get new plugs. The ones I have are only a few months old (denso europarts cheapies) the engine is fine at low revs, he said my plugs read upto .8 instead of a maximum of .5 if anyone knows what that means? He also said the maf was reading 40grams, and that was low???