Mitsubishi Repair: car will not start, mitsubishi cars, wire colors

Question
QUESTION: Hi Kevin:
i have a 2003 Mitsubishi lancer OZ non turbo. I had service engine light on. checked the code which said to replace 02 sensor. I replaced the sensor it was a universal one where you have to connect the wires up to your existing connector. the wire colors were different so I was not sure what wires went where tried several combinations and after each combination the service engine light would come on after I had reset it. In the process of trying different combinations I think I shorted something out because the service engine soon light will not come on when you turn the ignition on and the car will not start it turns over but will not start. I check the fuses but all were ok. Do you have any idea as to what might be wrong thanks. warner

ANSWER: First thing you should do is try to install the old one back and try it. If this does not work then where talking a different ball game.
The last thing you want to do is go further into anything. Always back track if the car started before and don't now then Start from scratch.
If this starts then I would purchase a stock one from a dealer.
Also please make sure there is only one o2 sensor most Mitsubishi cars come with two. One before the car and another after the cat.

Try this out and let me know what the update is. I'll do everything I can to get this working. Thanks again Kevin



---------- FOLLOW-UP ----------

QUESTION: replacing the original 02 sensor did not help. When you turn the ignition on not start the service engine soonlight does not come on as it should. I connected the OBDII to read a code it displays ERROR. This tells me that the ODBII is not communicating with the car. Do you know what controls the service engine soon light. The engine turns over strong but never tries to fire.  Does the ECU have anything to do with the car starting and service engine soon light. Whatever controls the service engine light is the problem. Do you know what controls the light. thanks for your help.

Answer
Yes the ECU/PCM  controls the Check Engine light.

While installing the new o2 Did you disconnect the battery?

The other thing is your reading of a standard code reader you might have to get this to a diag machine.

I tell you the first thing I would look at is your ignition relay. Maybe while hooking the o2 up you could have shorted it out.
What makes me worrie is if you didn't disconnect the battery you may have shorted one of the Dios on the ECU/PCM. If that is the case that would have to be replaced. NOT FUN!! Price wise.

I would check relays like you did with the fuses and see what you come up with.

Hope this helps if not please contact me again and we will keep trying. Thanks again,Kevin