I just got this 01 Durango (5.9) today (given to me from my father-in-law) and knew it had a couple of problems.

It gives code P0302 code (mis-fire) but when it failed emissions testing they noted "Fuel Sys - o2 Heater" and "EGR Sys KEOR Failed".

Shouldn't a bad o2 heater throw a code too? I have check for codes myself using the method in the sticky and only get the P0302. Any thoughts?

Also, how many o2 sensors are on this thing and how do I determine which one has a bad heater?

Thanks for any help guys!

EDIT: I just ran the VIN and I have the 4.7, not the 5.9. I bet my father-in-law has been thinking wrong all these years

 

P0302 Cylinder #2 Misfire

You have 1 pre-cat and 1 post cat 02 sensor.


Give it a tune up with Champion Copper plugs gaped at .040, OEM wires or Mopar performance, cap and rotor with the upgraded Brass contacts (your local auto parts store). If it continues switch your injector with a different one and see if it throws a code with the other cylinder.

Most likely your issues are directly related to you tune up parts.

 

he told me he just replaced the plugs and i found some boxes of NKG (or something like that) in the glove box. i'll try some champions and see where it gets me. also, where do i go for oem or mopar wires?

thanks.

 

dealer will have mopar(oem) wires, but msd 8mm (i think ) are just as good, if not better

 

thanks i will track some down.

any other thoughts on how to figure out which o2 sensor (heater actually) is the bad one? i think it is weird that the emission inspection stated it was bad but i am not able to pull a code. could it be something only seen when plugging into the computer?

 

if the o2 sensor is heated it will have 4 wires going into it, i believe an unheated sensor has only 2, see if both sensors have 4 wires going to them and if only one of them does you have your answer, otherwise i would say i need the code to give you a better answer

 

He made a mistake. His motor is a 4.7L and there are no wires on that motor as it has coil overs.

 

this is a true statement, however, is still need to figure out which of my 02 sensors (heater) has gone bad.

thanks for your help so far guys. this forum has been great!

EDIT: i called the dealership today and they tell me there are four o2 sensors?!?

EDIT2: i pulled #2 plug and guess what i found? RC12LC4
the gap is at .44 and the plug is soaking wet with gas. looks like coil #2 isn't firing. i am going to swap it with #4 and see if my code moves. i'll cap down to .40 while i'm at it.

 

Sounds like your on it!

 

all plugs were .44 or so and they all looked amazing except for #2 (which besides being wet literally looked brand new).
i swapped #6 coil for #2 (while resetting the gaps), reset the computer and it fired and idles great!

it was making some smoke during take off the first few times but as it has been sitting for a couple years it could be bad gas. i filled it up and drove a few miles at varying speeds/accelerations and so far have had no other codes or stumbles.

i am going to borrow a friend's scanner to see if anything shows up, but so far we're looking pretty good.

more to come....