My truck tripped the CEL and showed the P0138 code (first off I want to mention that I like the way my Dak shows the code rather than having to count flashes like in my Neon!).

I found the post stickied above that litsed the codes (I figured it was an O2 anyway since the truck hasn't gotten great gas mileage lately). Then I searched a bit more on these boards and I found a post that said that 138 was the "downstream left" sensor. Is this accurate? Does this mean we got 4 sensors on the 3.9L? I'll probably bring it to AutoZone tomorrow to have them read it anyway, but the one nearest me gets pretty busy sometimes.

Thanks a bunch in advance.

 

should only have three i believe. one for the y pipe and one in each cat

 

You either have 2 or 4 oxygen sensors.

 

Well I guess it's off to AutoZone before work tomorrow to get them to read the codes for me and to grab a Hayne's manual. Then I'll get it up on the ramps and see what I can see...