Surging Cold Idle

[ejack8850]

Engine idle surges until warm--may stall. Codes suggest Mass Air Sensor, O2 Sensors, EGR--could it be problem with warped plastic intakes. Is there an effective remedy? Thanks for your suggestions.

 

[RonD]

A lot of codes there.

Computer doesn't/can't use O2 sensors until they are above 650degF, so they won't be the problem on cold engine.

Intake gasket vacuum leak could seal itself as metal expands but that would be a long shot.

4.0l is known for dirty MAF sensor issues so that would be my first stop, can of MAF cleaner spray, don't use carb or brake cleaners.

You can test the EGR valve/system with engine idling, remove vacuum line on EGR valve, that line should NOT have vacuum present, put your finger on it and if you feel a vacuum then EGR solenoid is leaking causing EGR valve to open when it shouldn't.
Now put your own vacuum hose on EGR valve and suck on it, engine should start to miss and if you create enough vacuum or hold it long enough engine will stall.
If applying vacuum to the EGR valve doesn't change idle then replace EGR valve, you can try to clean it first, but make sure it opens and closes all the way before reinstalling.

Remove IAC Valve and clean it, not hard to do.
Before installing hook up it's wiring and turn key on, valve should open all the way, unplug wire and valve should close all the way.