‘99 5.9 V8 Durango Stalling in N & Park.

[Brxndon]

I’ve had my ‘99 Durango 5.9 4x4 for just over a week now. I’ve had nothing but issues since purchase. Specifically at red lights and warming up before leaving for the day the engine will stall unless i rev up the RPM’s. I’ve replaced IAC, MAP, TPS, Air filter, Spark Plugs, thoroughly and properly cleaned TB AND replaced TB gasket, and I’m lost where to look next. I brought into mechanic who said it was IAC or IAC short between IAC and PCM. He said he couldn’t do any further testing and referred me to an electrical expert. She starts up fine but after about 5-10 min the idle drops from 800 rpm to 500-300 then without revving up it will stall. Highway driving is a dream but in the city this is killing me and I just want it fixed no mater the f****** cost. If anyone can be of help let me know. This is a mudding BEAST and I hope to bring her out with our fleet this spring if she’s up to par. I should also add the previous owner was a heavy mudder aswell. Could the fuel pump or filter be causing this? Is the mechanic onto something with a short between IAC & PCM? Do I have a faulty PCM? If ANY other info is needed I will promptly give it. I will be watching replies to this thread constantly. I’m looking to have this bad boy fixed as soon as possible because even thought the MPG is **** I absolutely love driving my rango! Only codes it’s throwing are IAC & o2 sensors BUT it is straight piped and o2 sensor harnesses are ripped out and taped off.Thanks for all the help in advance! Ps I am taking it upon myself to make sure if the problem is resolved to post the end result. Specially because if other owners had done the same I wouldn’t be posting this thread in 2020.

[shorod]

Welcome to the forum!

Do you know the specific code numbers that it currently has for the IAC and the O2 sensors? If so, please post them.

Do you have a scan tool, or access to one, that will allow you to monitor the datastream while driving? It would be beneficial to monitor a few parameters when cold (and running okay) and again after the 5-10 minutes when the issues start. Seeing things like ECT, MAP, IAT, STFT for both banks, LTFT for both banks, fuel rail pressure, and there are probably a few others I'm not thinking of currently.

Since it starts cold fine and idles cold fine I don't really think the issue would be a non-functioning IAC (and therefore I don't expect a faulty IAC or short or open in the IAC wiring). I'm thinking more something related to the engine getting to temperature and entering closed loop. The PCM does use readings from the O2 sensors to manage the air/fuel ratio, so having the O2 sensor wiring cut and taped up could certainly be contributing to your issue too.

-Rod