Rough idling, stalling, and cranking issues
 

I have a 2005 Hyundai Tucson GLS. I am having issues with my car idling rough, jerking forward, and then stalling....usually while slowing down to turn, coming to a stop, and or while accelerating from a stop. it'll start back up but its difficult for it to turn over. it'llcrank longer than normal and then it seems like it'll catch and start up. The OBD2 scanner threw out several codes. P0171, P0174, P0335, P0420, P0430, and P0650 (this one explains why my check engine light lit up). I've taken it to a mechanic several times but once the problem seems fixed, the issues come right back. The things that have been done to fix the issues are...MAF sensor replaced, throttle body position sensor replaced, throttle body valve cleaned, tune up (all spark plugs cleaned or replaced), idle air control valve replaced, pcv valve replaced, and the crankshaft position sensor wires repaired (but not replaced with new sensor). its still stalling while coming to a stop or in park. the rpms go high for no reason (parked or slowing down), jerks forward and when it stalls its having a difficult time and repeatedly cranks when starting the car. it'll eventually start but not like it should. there doesn't seem to be a pattern of when the rough/high idle or stalling will happen. it does it when it wants to. but I have noticed it'll almost always do it after it rains for some reason. I bought a new crankshaft position sensor, an o2 downstream sensor, and a o2 upstream sensor but I'm having a heck of a time figuring out the correct locations for the crankshaft position sensor and the o2 sensors. I am at my wits end but I'm trying to figure out what I can do to fix it properly. am I on the right track or way off base with these repairs? any help would be greatly appreciated!!

From the symptoms you describe and the work that was done, leads me to believe your mechanic is guessing and you are paying for it.
I would consider having another "qualified" shop look at it and "See what the scan tool Parameter identifiers " show. It's like the doctor, when he looks at your blood work he has some idea of what may be going on. The same with the technician when he looks at the data he gets some idea of what is wrong because when he sees it he knows if it is right or not.

Thank you for the update , glad you found the problem and sharing the solution with us here.

I do have a concern and that is if a rodent made a meal of the wire covering, which is very common by the way, they get into the places you would never expect and it is quite challenging to find and repair their damage . At least your mechanic will keep an eye on your vehicle now for any repeat meals !