Hey chaps bit stumped here, first off car details.
Audi a3 1.8t 20v 8l 52 plate, AUM engine code, k03s turbo, standard map.
Aftermarket exhaust from turbo back
2.0t coil pack conversion
New copper ngk plugs gapped correctly
New maf from audio
New turbo so long I'd (n249 I think) from audio
New dump valve from audio
New pancake one way valve from audio
New pcv valve under inlet from audio
Throttle body cleaned and calibrated in vagcom, new gasket
All new pcv hoses (every single one)
New IAT sensor from audio
Boost pressure leak tested to 25 psi (no leaks)
New battery
New fuel filter
Issues it's having
On and off cold/hot starts car feels lumpy, idle is hesitsnt, requires more throttle than usual to pull away.
Rev counter doesn't sit right, as in at idle the revs seem to 'bounce' around, not huge numbers, but enough that the needle never sits still (around a few hundred rpm dips)
Turning OFF THE aircon, which makes it idle lower, the idle seems noticeably lumpier.
Some days, get in the car, warm it up, rag it and it pulls hard, other days feels like I could get out and push faster.
A loud audible 'whistle' when driving hard, SOUNDS like a pressure leak, but tests aren't showing anything (including a smoke test)
Getting engine codes
BANK 1 LEAN
o2 sensor out of range (along those lines)
Pressure drop between turbo and manifold
Known issues.
There's a small ticking sound when accelerating, think possibly turbo to mani gasket?
When doing the exhaust swap, we noticed a Crack in housing near wastegate, this was about a year ago, although at the time it didn't seem necessary to change.
Cam cover has an oil leak, need to swap the gasket.
Sooooo anyone got any ideas?