It started out as a typical check engine light diagnosis. A 2006 Honda Accord came in needing diagnosis, and the customer said work had been done previously elsewhere, but they weren’t sure what.
The car had two codes, one for the EGR System, and one for no signal from the knock sensor. I couldn’t diagnose the EGR problem with the knock sensor code still present, so I started by diagnosing that. The first thing to check was the wiring, and when I opened the hood, I found out why there was a problem.
Somebody had previously attempted to fix the lack of signal from the knock sensor by just splicing in their own wire. After their first attempt failed, they spliced another wire into that one and ran it all the way across the cowl and into the car, where they spliced into the wiring harness near the PCM. I don’t know if one of their splice connections is bad or if there’s a break somewhere else in the wire, or if they even connected to the right wire inside the car, but the only way to really be sure to fix this would be to replace the wiring harnesses.
I priced out several hundred dollars of harnesses, and noticed that the way one goes through the firewall is behind the heater box, so most likely the dashboard would have to come out. All this was adding up quick, and by rough guess this would at least $2000 just to fix the knock sensor code. After that I would have to diagnose the EGR problem, and on top of that, the annual state inspection was expired and they had some suspension problems that would fail inspection. On top of all that, both front jacking points were rusted out and collapsed, so with all these problems, this car is not worth fixing. The thousands of dollars it would take to fix, without even touching the rust, would be better spent on another used car.
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