Hello all, I'm new to this forum and this is my first post, although I have been reading through the forum with great interest for afew months now. An excellent forum I must add! Right.. I bought my car approx 3 months ago, and I must say I love it! It's a car known on here nobbers old one white s3 with lovely mods it's running a custom map but is approx stage 2+ The problem started as a hesitation at approx 5k revs (under boost) so after reading on here I found posts which suggested to change the coils, I've changed all 4 and it's still the same. Again after further research on here I changed spark plugs, all 4 changed for new oem plugs (originals car came with are denso racing plugs) the oem plugs were still the same at first hesitation at 5k rpm but then after afew days it wouldn't boost at all with this plugs in... Back to the forum for more research and found a very helpful thread on spark plugs and coolness levels etc, so I purchased a set of ngk iridium xi plugs 1 degree cooler as recommend for stage 2+ in the spark plug post on here. Now the car misfires randomly under boost, and it's a lot worst with these plugs in, I have taken a plug out after a day and it is quite black. I have also purchased a vagcom from the bay and no engine faults showing other than maf which I disconnected to rule out as seen in yet another forum post! Maf fault cleared straight away. As you can see I have tried to research on the forum first and have spent quite a lot ruling out things and still none the wiser! Any help would be greatly appreciated thanks gary