ok, i got no idea where people are getting 4 o2 sensors on the v6 3.9l. i have a 2000 dak w/3.9L and have 2 o2 sensors. 1 up, and 1 down, and thats ALL what the wiring harness allows. ive been having a stalling problem, after much discussion, i truly belive the crankshaft position sensor is the CAUSE, so i would advise checking yours. it is on the back of the passenger side of the block. between the block and bellhousing.

 

cali emissions is 4x O2, non-cali is 2x O2, plus or minus the year differences as well, I believe. I never did get a firm answer. But you have 2x and I have 4x. 4x sucks IMO.

 

My V6 has 4 total. 2 on each cat.

I'm Canadian too so maybe that has something to do with it?

 

maybe it was just the trucks sold in MA? maybe 00DakDan can chime in on this one.. but as for the OP, try your Idle Air Control, or your Crankshaft Position Sensor. i know my truck starts an runs (struggles) then dies. i pulled the CPS, and its toast. replacing today.

 

Just because you don't live in CA doesn't mean you don't have CA emissions. MA and many other states do, or the Federal equivalent.

Depending upon the year there are different emissions packages. In '01 for example, there was the NAS, NAE, and NAA. NAS and NAE both would have 4 O2 sensors. The NAA would only have 2.

 

I haven't had the problem at all since I made this post, except for one time, and I was thinking to myself, what could this be that just ONE kick of the gas pedal would clear up, and my mind went to this. I think I had one of these stick on a Ford Taurus about 20 years ago. I'm going to check this out first as soon as it starts acting up again. Then go down the list. I bought a hydraulic cable crimper at harbor freight yesterday and got my quick disconnect done on my winch. Very happy about that. The last step on my rebuild... DONE. One bolt one plug my winch goes on or off the bumper.