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Oxygen Sensor Wiring

PostPosted: Wed Aug 09, 2017 11:56 pm
by celi703
Does anyone have a oem oxygen sensor female connector? The reason is ever since I replaced the oxygen sensor the stock wiring had one bad connection and I decided to get rid of the connector and crimp the connections. Now the car will idle rough during start up every time with the check engine light on. But will idle normal after two or three minutes and the light will go away. Does anyone have any suggestions whether the connections should be crimped or soldered?

Re: Oxygen Sensor Wiring

PostPosted: Wed Aug 09, 2017 11:58 pm
by underscore
Either should be fine if done well, and sealed properly. What CEL code does it have?

Re: Oxygen Sensor Wiring

PostPosted: Thu Aug 10, 2017 12:09 am
by celi703
Code 21 but only comes on for about two or three minutes with rough idle. Then smooths out and the light goes away. The sensor is new and changed it because of the check engine light before and now it does the same thing so I think it has something to do with the wiring.

Re: Oxygen Sensor Wiring

PostPosted: Wed Sep 27, 2017 1:02 am
by 93celicaconv
Code 21 involves the oxygen sensor, either a signal problem or a heater circuit problem (or both). You said you had to crimp wiring back together. Are you sure you reconnected each wire to correctly (i.e.; brown-to-brown, yellow with black stripe to yellow with black stripe, etc.)? If you cross-connected your repaired wiring, this would certainly cause a problem.

On a side note, the sensor output signal wire to the ECU is sealed/shielded to prevent noise/distortion of the signal. It is possible you've affected that shielding with your repair. But it sounds more like a heater circuit issue in that your problem goes away as the engine warms up, indicating the signal wiring may be good, but the heater circuit is not.