I've been dealing with some strange issues for about 9 months now on and off and recently it led me to think the opti was going out..but now I'm not so sure. While looking for the source of the problem a few weeks ago I discovered the source of my ABS INOP light that came on occasionally. I found the heat shield had burned off and the insulation was burned off most of the wires causing them to short. I pulled that harness and heat shrinked the wires and added new heat wrap tape and also re-routed the harness further away from the headers. I also discovered the heavier harness that goes to the starter is pulled tight bringing it right up against the header. The heat wrap insulation is still there but it looks badly burned leading me to think the wires inside are burned and shorting together. My question is what wires are in there? I know the starter (+)lead, solenoid , and a ground wire are in it...but what else? Knock sensor? Oil pressure? Anyone know?

 

The harness that goes to the starter has the solenoid lead, knock sensor, PCM ground and O2 sensor wires for the RH sensor.

http://shbox.com/1/harness.htm

 

That would certainly explain the issues I've been having. I'll climb under the car and start taking the harness loose so I can see just how bad it is. Hopefully this is it and I won't have to change the opti.