I have some questions regarding O2 sensors. I got an SES light a few weeks ago. Went to Autozone, and it read a P0136 code. Bank 1, sensor 2. I spent the $60 and bought the sensor figuring I got 110K miles out of the original, so why not replace as I go. The parts guy said that Bank 1 is drivers side, and since I found no info otherwise in my Haynes manual, I was in agreement. So I replaced the sensor as well as replaced my PCV valve and generally looked things over. After reconnecting the battery to reset the codes, the truck has been drive about 400 miles without a hiccup. Until last night when the SES light came on again. Again I went to Autozone and found a P0136 code. I reset it with the code scanner, but expect this to return.

My question is, which side is bank 1? Did I replace the wrong sensor?

 

Bank 1 is the drivers side. Sensor 2 is the rear most sensor (after the cats). I found this link from another post and it's most informative.

http://www.obd-codes.com

As you scroll down the list, click on the underlined ones and it gives a brief discription of the code series and some other things to look at.

Good luck!

Mitch

 

Thanks Mitch.

The only thing is I can't find the anywhere that specifically states that Bank 1 is drivers or passegers side. From searching here I get about the same response, some say passenger, some say driver side. All are what I consider reputable sources.

I'll search a bit more, then if I have to I'll call the dealer.

 

Ah - I found it!

Bank 1 is always the cylinder bank with the number one cylinder. On a 4.2L (maybe I should have been specific here) the #1 cylinder is front passenger side.


Wrong side.

 

Humm... Well, then that site I got the info from is cr@p then!! They pretty much state that bank 1 is drivers and bank 2 is pass for many of the codes that have a 'bank' side to it...... I think I even saw somewhere that bank 1 was the opposite side of cylinder 1 stated somewhere.....???

Well, it's a 50-50 chance at any rate!

Good luck!

Mitch