1998 SOHC Intermittent Idle Surge

[aksasquatch]

Hey all,

Last year I bought an 03 Ranger with a blown engine and swapped the motor with a SOHC 4.0 from a 98 Explorer with 80K miles. From the get-go, the truck would occasionally and unpredictably surge at idle, sometimes to the point where it would stall out. I've driven it around 100 miles since, and it drives/sounds fine at highway speeds, but at traffic lights, I'm always rolling the dice as to whether it'll stall or not.

What I've done so far:

• Fuel filter
• Lower intake manifold gaskets
• Checked for vacuum leaks (just squirted water around, nothing too fancy so I'm not 100% confident.)
• Replaced PCV
• Cleaned IAC
• Cleaned MAF
• Replaced plugs
• Bled cooling system
• Cleaned injectors (when assembling engine - cleaner sprayed through each one)

Codes thrown after clearing DTC's:

• P0446 EVAP control vent malfunction
• P0135/P0141 O2 Sensor 1 & 2, bank 1 - heater malfunction
• P2196 O2 sensor 1, bank 1 - signal stuck rich
• P2197 O2 sensor 1, bank 2 - signal stuck lean
• P0172 System too rich (bank 1)

• C3301
• C1301
• C1521
• B15A8
• B1E01
• C3500
• P00DF

Those last codes don't come up with a description, and to my knowledge this morning is the first time they've been thrown. The O2 sensor codes will either be rich or lean, I've cleared several times and they aren't consistent. It has also in the past thrown P001E Intake camshaft profile control A, bank 2 - circuit low.

My other concern, though I doubt it's related, is that the Ranger's engine came with no EGR system. Were some of the trucks delivered this way? Couldn't find any info on the web about it.

Here is a video of its typical behavior, though it doesn't dip low enough to stall.