I ended up ordering the OEM IAC, MAP and TPS. That was a quick $250. I'm still going to smoke the vac system and make sure it's not a leak.

 

Check for vacuum leaks. You may find disconnected hoses, or hoses with cracks. Spray carb spray or starting fluid on the hoses to see if the idle changes.

I'll never forget how much the drivability of my truck improved when I replaced the TPS. I replaced it because the truck had begun stalling when coming to stop. It fixed the problem, but also made the truck accelerate much smoother, with a linear power delivery. Prior to that, acceleration was herky jerky. It was as if I was driving a big caddy all of a sudden. It was a pretty dramatic change.

 

I smoked the vac system yesterday. First off just let me tell you, if you ever buy one of these that use mineral oil make sure you can ventilate your work area when you are done. The smell is brutal and has a whole lot of hang time. Unfortunately I did not find any leaks. I was really hoping it would be something that simple. So I'll wait for the new OEM sensors to come in and see if they help at all.

 

For today's update let's talk about OEM parts. I changed the MAP and IAC with aftermarket ones. I have replaced the IAC before with an aftermarket one so I'm pretty sure the issue was with the MAP. After replacing them the truck ran like complete s$%t. The idle was barley 500 RPM and it would stutter and stall. After a few days it would hold idle but it was still very rough. I replaced the injectors, plugs and coil packs as well as lifters and rockers. After reconnecting the battery I had another 3 days of horrible idle until it improved to just a bad idle. I just installed new OEM IAC, MAP and a TPS. After reconnecting the battery the thing fired up, no stumbling, no shaking, no issues at all. It idles perfectly from cold to full temp. You can goose the throttle and it comes right back without dipping below 500 or so RPM. All without having to run it for a few days to get the PCM to learn the new sensors. I'll run it for a few days and report back but it is already a vast improvement. I would highly recommend using only OEM engine sensors on this vehicle. I have a lot of other aftermarket parts on it that have never been an issue. I've run aftermarket engine sensors on other vehicles without issue. This thing just does not like them. At all. Granted it was $230 for those 3 sensors versus $75 for the aftermarket parts but once you factor in all the headaches, tools, other parts and a trip to a shop to figure out the problem only to have to buy the OEM sensors anyway, I would have saved about $800 if I would just have used the OEM parts in the first place. Buy once, cry once and be done with it.

 

That just seems to be a Dodge thing. They simply do NOT like aftermarket sensors, even some of the better quality ones......

 

I'd disagree with the standard motor products recommendation. I've had several of their sensors fail on my Durango or not work at all. A TPS, CKP, and an IAC valve. Also an ignition coil from them failed.

 

I had good luck with their TPS for my 98, (in my sig) but yeah, for the most part, and especially crank/cam sensors, Mopar is the ONLY sure way to go.

 

It's got to be a PCM programming thing or hardware detection range. I bet the OEM sensors are made to a much tighter tolerance than the aftermarket and the computer just can't adjust itself to the wider aftermarket tolerances. It would make sense because some people get away with it and most don't. Occasionally you'll get an aftermarket sensor that's actually made close enough to the OEM tolerances for it to work.

 

I can usually find Mopar sensors online (whether it be Amazon, ebay or some other site) cheap enough to not make it worth the hassle of aftermarket. Sometimes, even cheaper than some aftermarket.

 

The aftermarket sensors were a known issue discussed back around 2004 to 2005 time frame if I recall. We were discussing just go back to factory sensors. pay more, but no issues. I think the aftermarket sensors were build by different manufacturer and their specs were quite tuned for factory pcm to recognize. All my electrical stuff to fix back in those days were all strictly mopar replacement parts. Not so much today. It's getting harder and harder to find factory parts for our 20 year or more old rides... I would not trust pick and pull to get them unless you don't have a choice.