1.8t misfire

A buddy of mine has a 1.8t A4 and has problems with it misfiring in the higer revs and the idle fluctuates between 800 and 1000 rpms. It only seems to do it randomly when you have your foot to the floor (usually starts to misfire at about 4k rpms). The previous owner pretty much drove it and changed the oil since the day it was purchased. So far the maf has been replaced as it was bad, diverter valve was stuck closed, had a bad coilpack, and replaced the vaccum lines. I keep telling him its his spark plugs, but he doesn't believe me as he just put in those crap copper plugs. I know most people recommend the ngk platinum pfr6q's. Any ideas before he throws in the towel and takes his car to Audi?

air filter fuel filter and yes the plugs hsnt cracked the intercooler?

i had the same sort of problem with a misfire under load at highish revs just when the boost kicked in bout 2.5/3k it was the plugs that were had it, put some ngk pfr6q's in and it has been fine ever since.

make sure that all the coilpacks are fully pressed down,as i did an s3 that missfired when you floored it.and it turned out to be this.

you wouldnt think that it was that important but it is.

Hi 1.8 and 1.8t have been known to have broken wires in engine loom ,
something to check !!

^^^

Got a good point.. But ya sure its a missfire and not what they call (spiking). to much boost maybe or the actuator could be on the way out??

its gona be the air mass meter of a coil pack