the only way that is possible is if both were model year 00 or one was a 00 and the other an 01

 

Yes, what shrp said because they did the cosmetic overhaul in the 2001+ model years. Apparently one model year was a 2000 and one was a 2001, and you'd have to either pull the build sheet or ask Dodge help to know which model year it was.

For instance, mine was a 2000 model year but I bought it in January of 2000 and it was manufactured in November 1999.

 

I replaced the rear oxygen sensor yesterday an it helped but still is running a little rich The connector on it was damaged and it was not changing on the scanner before it was holding at .740V and not changings so that showed me that the sensor was being lazy. The fuel pressure is 45-50psi, vacuum reading is 9.4"-10", I pulled the injectors to see if they were leaking and none of them were leaking I let it sit with the pressure gauge on it and it leaked down to 10 psi withing 3hrs of sitting. oxygen sensor readings were O2S11 .100-.900v, 02S12 .100-900V changing rapidly. Ignition advace was 9-20 degrees depending on rpms. ST FTRM (%) 0.0-3.1 CHANGING RAPIDLY , LT FTRM1 (%) 3.9 HOLDING. NO ENGINE LIGHT. This thing runs great and hickups every once in a while and then runs great after that. I sets the DTC without the light P0172. I believe the fuel pump or pressure regulator is not holding but fuel pressure seems to be alright. It is still in learning mode to, I reset the computer when I installed it, by touching the positive battery cable to the engine block and grounding it with the neg. still hook up for 30 seconds. I'm lost it just seems like it is doing great untill it slows down to idle and is in closed loop is when it happens once it does it smooths out and is fine after that. I was driving it up and on ramp this morning and and it popped out of the exhaust four times and then smoothed out. I just don't know what else could be causing it. I replaced everything on the timing and ignition side and checked everything on the fuel side.

 

the rear o2 sensor (after cat) does NOTHING except tell the computer if the catylitic converter is funcitoning properly, should have exactly 0 effect on driveablity and running of the engine.

sounds to me like the anti-drainback valve is gone, its part of the pump, the truck will run fine w/o replacing the pump, just make sure to prime the system before turning it over (turn the key to on and let it sit for 10 sec or so)

you did it WRONG!!!!!!!!!!!!!!!!!, you may have fried the PCM doing it that way, the CORRECT way to reset the PCM is to disconnect the battery negative cable, and leave it off, go inside and turn the key to start for about 30 seconds to drain the system, then put the cable back on, and start the truck, let the rpms settle, then shut it off, you are now done.

my bet is computer problems based on the way you reset the PCM

 

kinda figured my post and reply would get lost in the catacombs,

 

The fuel pump will leak down a little from hot motor to cold because of the heat. When the fuel cools down it condenses and thus the loss of some PSI.

P0172 1/1 Fuel Sys Rich

Well that right there is a bad pre CAT O2 sensor.

+1 Sharps, you didn't reset the PCM, in fact you could have fryed the thing! https://dodgeforum.com/forum/1st-gen...ine-light.html

 

How would I have fried the PCM with the negitive cable still hooked to the battery, and then grounding the positive cable to the block? I didn't send power back to the computer at all. I found this procedure on this website. I drove this the last two day and it has been running great without problem now just the other morning once. You say the pre cat oxygen sensor is bad. It is reading and changing rapidly like it is suppose to how is that sensor bad I always thought as long as it is reading between .000-1V and changing rapidly then it is working, but please explain I'm not a driveaiblity tech.

 

By dissconnecting the neg cable and turning the key, you're draining all the power FROM the PCM and other modules to the starter motor. By dissconnecting the positive battery cable and shorting it to ground, any power still stored in the PCM is now going back into ground and pushing it TO the PCM and other modules. The capacitors inside the PCM need to be drained to a motor and not back into circuits.

 

by touching the positive battery cable to the ground you are sending a shock back thru the system, ever have a power surge hit your house while you computer was plugged directly into the wall? what happened? yup the something inside the computer got fried, same idea here.

and no you did NOT find the procedure that you used to reset it on dodgeforum.com, i guarantee that (and if you did i would like to see where so it can be corrected)

here is our procedure for resetting the pcm

 

Yes theres q reason you should never touch to positive to the negative ever. Good analogy shrp and is very true.

You should have just asked how to reset the PCM because touching the battery to the block isn't how you do it. Like shrp said the correct procedure (also found in the stickies at the top of the page) is turning the key with the positive off the post.

Good luck and happy trails!