Rough idle / lean after warming up | Ford Explorer - Ford Ranger Forums - Serious Explorations
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Rough idle / lean after warming up


New Member
May 25, 2023
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City, State
Liberty MS
Year, Model & Trim Level
2007 Explorer Eddie Bauer
Have a 2007 Explorer EB 4.0 V6

Did a search, but didnt turn up anything similar

Recently it has gotten where when it get to 165-170 degrees (per a Scan Gauge 2) it starts running very rough, then dies.
Before, wife said it would occasionally have a “dead pedal” so the throttle body and pedal were replaced. She ran it a while and now this.

Today was the first day I have had time to mess with it, due to work, (and having a 3rd vehicle)

Vehicle has had plugs, wires, tb, pedal, coolant temp, crank position, and fuel rail pressure sensors (at which time upper intake and valve cover gaskets were replaced) in last 10k miles

Only codes it is showing at moment are P2195 & 2197

MAP sensor was reading steady 4.4 until it warmed up then it went erratic with the idle.

Runs perfect until it gets up to operating temp.

At what temp does egr start to open? What else is temp controlled that I need to check?

Been wrenching on my own stuff for 40 plus years, but the newer electronic stuff stumps me now.

Thank you for any input

With both sensors reading lean its unlikely the o2 sensors are bad or its a pcm issue. It still could be but unlikely. things it could be; wiring, a vacuum leak, fuel pressure, egr valve, pcv valve, or anything fuel or air related. on your scan tool watch the live data for fuel pressure, b1s1 & b2s1 o2 sensors and confirm they are reading lean and fuel pressure is not low (should be ~30psi or more). If you have freeze frame data look when the codes where set to see if anything looks off.
The egr valve should always be closed at idle if it is leaking it would be just like a vacuum leak possibly causing the symptoms.
while I am no professional I would lean more towards wiring issue or vacuum leak because you have codes for both sensors.

I am guessing this issue started after you had all the work done? If so look over all the hoses that connect to anything that may needed to be removed for the work that was done. its possible that a hose was not connected or not connected all the way and fell off. also may be a good idea to check for vacuum leaks in around the intake manifold just to be sure.

Plan to get back on it Tuesday. Thank you for the suggestions

Have a program to do Monday on those perished from our county defending our country.

Lest We Forget