Hey guys,

I’ve got a problem. I installed a 3-wire o2 sensor AC part # 25176708 and followed the instructions at http://www.sethirdgen.org/HO2S.htm as for wiring hookup. On terminal A I’ve got a good 12v connection coming from the MAF power wire. On terminal B it’s hooked up to the battery ground on the chassis. On terminal C I cut the old plug connection from the single wire o2 sensor so I could use the stock connection for the signal wire to the ECM.

Now the problem, using Diacom the o2 millivolts reading 18 to 24 at idle. The fuel status is showing a lean condition at all times even in closed loop. Even if I rev the motor up to 3000 RPM’s the o2 reading don’t change too much. They may get up to a hundred or so. I even confirmed the reading at ideal at the plug connector using a digital voltmeter. Could I have gotten a bad o2 sensor? I’m going to check tonight for an exhaust leek.

An ideas or suggestion would be appreciated.

Thanks,
Chuck

 

Ok guys here’s an update.

I couldn’t find an exhaust leek so I swapped back in the original single wire o2 sensor. Now my o2 reading are back to normal. I’m thinking I got a bad o2 sensor. The problem is I ordered if from http://www.gmpartsdirect.com/. Not sure about there return policy so I’ll have to look into that.

Has anyone installed the three-wire o2 sensor AC Part # 25176708 and had problems?

Is there anyway I could test this three-wire o2 sensor?

Thanks,
Chuck