2 days ago I posted about the bad Misfire, coil packs, wiring harness & MAF issue. Well I changed the 4 Coil Packs & plugs. Runs great except for some cold start misfire now. It's gone when the car gets warm. Mechanic says I need to change the wiring harness, is it deteriorating!!. Dealer says never heard of the problem before. So what you guys think ??!!. I was quoted $1800 to replace the entire wiring harness for the car, to be safe , cause who knows what's there that you can't see!!. The car 01 TTQC 180,48k miles. thanks in advance for your replys.

'01 180 TTQC amulet red, premium package, BOSE 6 Cd changer,Tint,fog light mod,non-resonated 3" custom pipe w/ 225 Dual exhaust,3.2 valance, H&R Springs,full K-mac,H&R spacers 15mm FR & 25mm RR,19x8 TSW Rocket5 GoodYear F1 G-D3, Audi 17x7.5 6spoke w/ Sumitomo HTR,Audi Bra with TT logo,Escort 8500