99 Dodge Durango codes P0505 and P0123

Have a 1999 Dodge Durango 4x4, 5.9L with Check Engine light the Diagnosis codes are P0505 and P0123. I would like to get it service; parts that were recently installed are Oxygen sensors - upstream and downstream and IACV- idle air control value. Wires seems to be OK. What else can be done?

change the throttle position sensor (TPS) very common failure on all of the mopar V8's and the 4.0 ltr 6's. Check the IAC circuit to be sure it's both grounded and receiving power when it should be. A better scanner might be able to actuate to see the pintle position change, Some sets of noid lights will plug into the harness and blink as the pcm commands the IAC

good luck and keep us postted

Jeff

After checking and changing the TPS and IAC and clearing the codes the engine light still came on. So with hard thinking and regretting I'll have to take it to a dealer. Of course they came up with the same codes as I did (big surprise) and told me these same things need to be change. I told them in the beginning that they were already changed and showed them the receipts. I told them to change them and guess what, the engine light was still on and they brought me the truck like everything was OK after paid $$$$. I did not leave the lot with it the only thing I did was reached in and started her up, and the manager was standing right there beside me. Needless to say they had my truck for a week, because they could not find the problem. I told them it have to be fixed, because the Holiday was coming and in the state of MD you will not passed the Emission Test if the engine light is on, they will not even look at it.

So to make a long story short the TPS, IAC, and the PCM was replaced and the throttle body was cleaned. The engine light was still on. I guess when you tell the dealer that you will take it somewhere else and refund you your $$$$ they find out the problem quick. Turns out the newly installed spark plugs gap was not set right, and the engine light is now not on. Now I'm wondering was it necessary to replace the PCM, IAC and the TPS. The truck runs just like a newer one.

who installed the spark plugs? I'm sorry you're experience at the dealer wasn't too positive, Working at a dealer I see lots of similar scenario's unfold and I'm kinda on the fence with alot of them! It can be tough to diag a vehicle that's had alot of sets of hands on it because the tech has alot of parts and procedures to recheck, as well I've seen brand new sensors and IAC's from some other manufacturers be no good right out of the box. A vacuum leak can throw you the same codes you had, the intake plenum is a common spot for this, so are wiring issues on the ASD circuit which posers up the IAC, TPS etc. Here's hoping that everything is resolved for you!

good luck and keep me postted

Jeff