hey i'm trying to clear my check engine light. the problem was o2 sensor bank 1 sensor 1 which is closest to the engine. I replaced the o2 sensor and found the old one had 3 exposed wires and i assumed they were touching. I tried to clear the code in every possible way i could (negative, back up fuse, ecu, scan tool). And it will always come on. Might the o2 sensor messed up the ecu by those wires touching?

 

Is the CEL light ON because a sensor is throwing a trouble code or are you unable to retrieve a CEL trouble code even though the CEL is ON?

 

its throwing it. i am trying to clear it nowm but it always comes back on. and there is no possible way to get rid of it. i think the ecu might be messed up but not really sure. i dont have that much time to chat cause i am on trial version right now.

 

If the same O2 sensor code is being thrown after clearing the ECU, then the O2 sensor circuit probably still has a bad wire. Repairing O2 sensor wiring is a tricky business.

 

could the ecu be bad or just the wiring? you can chat with me on aol instant messenger: ign uckkabuck

 

A bad ECU is possible, but typically pretty rare. I recommend that you first carefully recheck all the wiring with a multimeter (voltages and continuity). If your original repair involved cutting wires in the O2 circuit, those repairs should involve soldering.

I sent you an instant message (HondaTech address).

 

do you have the readings or a chart for me to check. like what are the voltage ranges and the ohm ranges

 

Check the downloadable 96-98 Civic manual for details -- chapter 11, pgs 11-84 to 11-94.

Your scan tool should prove very useful for the troubleshooting, if you have reasonable one.

 

hey thanks for all the help, but it was the ecu, i put my friends 2000 ex ecu and it cleared up the CEL and never came back on. i drove it for about 2xx miles already. i traded my si rims for his ecu and his rota group n