whats up all,

1994 acura integra ls

This problem is a killer, my cel will not reset, it keeps throwing a code 1,
i have replaced the o2 sensor twice with and ngk branded one and now with a denso branded one. i have followed all the precedures in my official acura service manual, checked the resistance on the o2 sensor it is well with in spec, checked to see if i have a short in my wiring harness, and i am reading 12.89 volts, to the oxygen sensor, i installed the o2 sensor with the car cold, let the car idle to operating temperature, turned to car off tried to clear the cel code while it was hot. i am completley stumped. the only option the book is giving me now is replace the ecu. is there any way to check the ecu without taking it to the dealer. like i said i have done every thing there is to do in the manual.

thanks,

Mrproul

 

Have you tested the ground at the connection?

I've seen this happen in the past:
The CEL is only going to display the code for the sensor that it is getting a "bad" or "faulty" reading from. Another sensor may have a prob (like a MAP sensor, for example) and is causing the O2 to get a bad reading or report faulty conditions.
Mechanical problems (that are not monitored by the ECU) can aslo provide the ECM with a 'false reading' by creating problematic conditions at the sensors (i.e. a vacuum leak can cause a CEL showing a MAP sensor).
This may not relate to your issue, but I thought I would throw it out there. If you're noticing some engine troubles you might have to look elsewhere for the problem rather than depending on the check engine light.

 

It sounds like you're checking the sensor preheater system (resistance & 12 volts). That would be good if you got code 41.

Code 1 is for the actual sensor, not its preheater. The actual sensing element should read like an open circuit when the sensor is cold. It should swing between 0 & 1 volt when it's hot & operating (hooked up - you'll need to backpin the connector). And it's a different circuit than the preheater.