Hello All,
Newbie here, hopefully I'll get us to speed quickly, I'm trying to get my Sons Durango squared away as it has to pass muster in 4 days to get shipped to my Son stationed in Alaska.

2003 Durango, 143.000 miles, 4.7, electronic 4wd. Just purchased 2 weeks ago. It is very, very clean.

89 miles after purchase it throws code 420, converter. Exhaust shop verified, worked with me to find a lower cost option than the $1800 auto part costs and installed an aftermarket that meets required specs.
I installed new plugs, new PCV and air cleaner, changed oil and filter, 211 miles later it throws code 440 evap system, it was showing symptoms of a failing fuel pump. It was the original fuel pump, so it was time, I installed a new aftermarket fuel pump.

Just before the EVAP 440 code it had a random rough idle when cold. Once it warmed up it was fine. After changing the fuel pump the random cold idle got worse,

I checked hoses/connections and replaced the EVAP cannister, Still has the rough idle. I put 20 miles on it at freeway speed last night, ran fantastic. Have not yet started it this morning. Its 39' out, I'm going to put a couple hundred miles on it to see what happens.

I'm on a very short time line to get this rig to the ship yard. Any insight at all would be GREATLY appreciated.

 

How old are the plugs, and what type?

 

I put new Bosch Irridium plugs gapped to .040. Only 100 miles on the plugs

 

That may be part of the problem. Dodges are notorious for just not liking the rare-earth plugs.... Might try swapping them out with coppers, see if anything changes.

 

Thank you HeyYou, I just 125 trouble free miles on it. The plugs I took out were AC/Delco copper. They look great, really good! They burned to a 55-60k gap, I'm guessing they had been in there quite a while.

I put the irridiums in as I was told thats what OEM was,

Thank you for the input. I'm going to drive it for another 15-20 miles in town, then 50 hwy and see what happens

 

Bosch has been around forever/ but 2 things I have had horrible luck with from them, are spark plugs (no matter which ones of theirs you choose) and O2 sensors.
For plugs I just stick with what has always worked on every Dodge I've had. CHAMPION. I did just put (I think they were double platinum, been a while since I bought them in a pile of goodies from Rock Auto. ) ones in my 4.7 last week, at 130k I think I might have pulled out what were probably the originals... looked like basic copper and the center electrodes were worn damneer even with the insulators. I dunno how it wasnt throwing misfire codes.
I too just bought my 03 and am going thru it "catching up" on maintenance. Bought plugs, PCV, all new hoses, a serpentine belt, front brakes (pads that came on it were fine but rotors were warped) 300 miles on new plugs and so far so good....
It dont matter what brand of vehicle I work on, I have never had good luck with Bosch plugs.
and if you use a BOSCH O2 I can guarantee you that itll be bad againin a year. Put an NTK in (same as what MOPAR used at the factory when new) and you wont have that problem.
I do this crap everyday for a living....