Hey everyone long time lurker first time poster.

I sank my jeep about 2 weeks ago in some deep water going through a mud hole. I've done several things to get it up and running again, but have run across some odd idle issues.

Steps taken post sinking:

New Starter
New Spark Plugs
New Air Filter
Cleaned Distributor
Cleaned Battery terminals
Flushed(Gunk High Mileage) and Changed Oil(several times)
Fuel System Treatment(Gum Out)
Cleaned O2 sensors(only ~month old)

Problems:
On idle the engine RPM will bounce from 250 to 750 RPMs, however it doesn't happen every time. If I place the jeep into neutral while sitting still, it seems to almost always avoid the bouncing RPM. Rarely does the jeep stall, usually gunning itself once the RPMs reach near 0(but occasionally it will stall). Sometimes if I let the jeep coast it will also bounce the RPM when it is near 1K RPM.

The check engine light also is on with a code of:
P0171 System too Lean Bank 1

Research:
My digging around has yielded that problems might be in the IAC, Vacuum System, or O2 sensors.

Conclusions:
Cleaning the O2 sensors should eliminate them as an issue, especially since they are ~month old.

Vacuum System leaks are a large undertaking to find and solve. Given that the engine was subjected to water, I believe that this might not be a likely problem.

I believe that my problem lies in my IAC. It seems that there is a gasket that needs to be dealt with when removing the throttle body to get to the IAC that can be easily damaged and can not be acquired from your neighborhood auto store.

Does it seem that I am on the right path?
What other steps should I take to get rid of this nasty idle?

Thanks!!!!

 

Vac leak issue sounds likely. The o2 could be bad already. It happens.. The TPS and IAC are possible. Plugs, wires, cap and rotor good? Doesn't sound fuel delivery related.. Dummy gauges all reading good numbers? Whats battery voltage at?

 

Battery voltage is 14. Haven't heard the term Dummy gauges? Plugs, wires, cap and rotor all seem good.

 

"Dummy gauge" is the term used when referring to your OEM gauges. Beyond unreliability, they only tell you when something is wrong, not what is wrong. Also, seeming and knowing are worlds apart.. Knowing what specific sensors are doing as far as voltage readings etc. is critical in proper assessment.. If you've got a friendly garage (that will do it for free) with a good scan tool see if you can get them to hook it up and give it a thorough check. This might provide some good specific information and a direction to go in. Good luck.