running poorly. Wiring harness??

Just a thought.

 

I say shop around.

I put new external oem cat harness on my Emodel cat about 6 years ago. I think it was about $600 right from cat.

I know cat stuff went up in price but shouldn't be that much.

Bought a new water pump for my E model 6 years ago and it was under $600. Just bought another last month , over $1000 now. Cat has just got out of control with parts lately

 

Gotta start from the ECM and work backwards, patiently, methodically...trace every single wire for damage and eventually it'll show up.

 

check and clean all grounds. Have seen this to many times. people think it wiring when in fact it grounding causing the issue.

 

I think the mechanic should/can use an ohms meter and be able to explain their diagnosis to you. I would not throw 2 grand at a wiring harness just based on assumptions. If you indeed need a harness he should/can jump wire that is causing problem and do another cat et test so you the owner can make a decision if you want to chance the spliced harness for a while or go ahead and buy another. Lots of repairs can be done to a harness. Complete engine serial number? Mxs run around 1000 bucks. That p number is not a cat part number and it should be if you need the harness from ecm to head.

 

Also could be a bad ECM we had a truck for two years cause intermittent miss fire to full out shut down. never the same thing twice but would run fine for months. If you could locate a test or loaner ECM to try and see if this cause of your problem.

 

Get a ohm/volt meter and a headlight bulb you can load test each wire and find the bad one. What's the motor doing? It will help to know which part of harness to check. And usually if its a good mech they can pin point it exactly to which wire unless it comes and goes type peoblem. First thing I would are both timing position Senor wiring.