oxy sensor code

**cavell** · 08-14-2013

had code 0140 for awhile. changed rear sensor. code went away. for 1 yr. code is back. along with 0102, maf, low voltage. changed maf and than i got code 1404, egr pintle range. what the bleep? so, 0102 is gone which is good but i still have 0140. i think the egr code is gone since i have not seen it in 24hrs but the 0140 remains. so, low or no voltage. does that mean dead or dying rear sensor?

**Scottydoggs** · 08-14-2013

check the wires to the o2 for damage.

**cavell** · 08-14-2013

Well, I did replace my trans last week. But I had 0140 before I did any work. I was very careful doing work. Did not yank any wires or break any connectors. Quite a smooth job for once. Did a trans in 2nd car last fall. Getting good at this.

**02NavyBlue** · 08-14-2013

What brand sensor did you install? I have the same code, and another (P0140, P0141). I'd use oem sensors since most sensors provide critical data for the computer to run the engine properly. A slight bit difference in aftermarket sensors can sometimes cause issues, or they may not last.

**Booba5185** · 08-19-2013

Originally Posted by 02NavyBlue

What brand sensor did you install? I have the same code, and another (P0140, P0141). I'd use oem sensors since most sensors provide critical data for the computer to run the engine properly. A slight bit difference in aftermarket sensors can sometimes cause issues, or they may not last.

Doesn't the secondary 02 sensor only verify if the cat is working or not? I was under the impression that the first 02 sensor is the important one.