2003 A4 1.8T TIP 130k Quattro wagon AMB
I rarely have to post on this forum since so many have posted before me.
I’m trying to bring back a neglected ’03 wagon and I also own a 01 A4 with 220k on it that runs like a dream. I purchased it with 75k miles and have done all maintenance since.

This 03 has been challenging and what I can’t seem to fix is a rough idle and positive air pressure at valve cover (oil cap rattles pretty hard if you loosen it)
I do own a Bentley manual & VAG
I’ve replaced the timing belt, water pump, tensioners, serpentine, thermostat, etc.
Completely went through the vac system with a fine tooth comb. All lines are clean and no leaks.
I replaced the spark plugs, MAF, fuel filter, DV, PCV, PRV and CTS
Insalled known good coil packs from the ‘01
Fuel rail was a mess and most wires had cooked and cracked. Fixed that.
02 sensors checked out fine on VAG
I cleaned the TB and did adaptation.
I’ve done nothing with the “N” valves

Thanks for the forum