Car turns over but will not start! (long)

[TimmyD]

Ok, here's the whole story. Last weekend I put in a new turbo back exhaust. We couldn't get the existing O2 sensor out of the housing, so i drove the car 1 block back down to my house. I ordered a new Denso O2 sensor and installed it last Wednesday. It took a little cranking until it finally started and idled fine. After 3-5 minutes of running the CEL came on. Turned the car off and started it again, same result (CEL). Took it for a drive, ran fine. Yesterday I go to start it, nothing. Cranks over but does not start. Pulled the plugs, one was totally bridged with carbon, the others had major carbon deposits. Changed them with new plugs, same result. I reset the ECU multiple times also. There are 3 wires that come out of the same wiring loom as the O2 plug. Two wires go to one plug on the water neck and one is by itself. These wires are disconnected (don't know for how long). Will this prevent the car from starting?

 

[talon1979]

Do you know why the car is pulling a CEL? I would try to find a datalogger. usually if a car turns over and will not start it the power transistor/control module has failed, but those are expensive so I would maybe try one off of a working car first. Before you try that you may want to make sure the timing is set correctly.

 

[TimmyD]

I think i found out what it is. I hooked an analog mulitmeter to it and checked the number of sweeps and it indicated "coolant temp sensor". The two broken wires going to the one plug is that sensor. Searching back through the forums indicates that the car will not start with this plug disconnected. Thanks for the help though.