[bass1175]

You can check you wiring harness by removing your airbox and tracing your injector wires back. check for cracking in the insulation, if you need a harness this can cost around 550.00. go to pcmahers website and check his project and you will see exactly what the cracking looks like.
The timing chain varies from who you ask, my dealer said they dont need to be tocuhed for 300k miles but some may say 150-200k miles. Listen for any clicking or taping near the front of the engine which can mean a loose chain. cap, rotor, plug wires are also expensive for this vehicle, but again what car wont eventually need that. find a parts website and browse the parts for pricing.