ishsgt

I have a 200 F150 with the 4.2 liter and recently it started surging, shaking, and bucking. Especially at idle. It runs good at acceleration. I cleaned the throttle body, checked for vacuum leaks, replaced the MAF sensor, and replaced the IAC motor. I got the code MAF out of range, Bank 1 lean, and Bank 2 lean. After clearing the codes the Check engine light has stayed off. I have aslo diconnected and reconnected the battery. Any suggestions on what it could be?

Hick

Harmonic balancer? (spelling) Almost the same problem but mine would only do it while in drive, put it park and it was fine, step on gas and didnt have any power at all and then it would do better once i got up to speed.
Well the keyslot on the "Harmonic balancer" was twice the size as it should be and it caused the timing to be off.

ishsgt

well it has good power, it just surges at idle alittle

jdf150

Try cleaning out the throttle body with some throttle body cleaner. Double check the vacuum lines and PCV valve.

Speedy Mike

DPFE, $70 part at advance auto, that will cause all three codes and is notorious for failing..

ishsgt

i cleaned out the throttle body, and i cant find any vacuum leaks. what is a dpfe

Speedy Mike

differential pressure feedback egr sensor. It controls a solenoid, that controls the vacuum to open and close the egr valve. Its an aluminum rectangular box with two vacuum lines going to it and a plug. I just replaced mine with the plastic one from advance autoparts. Also check the rubber 90* vacuum line that goes into the bottom of the plenum behind the throttlebody. also make absolutely positive you plugged the plug back into the MAF sensor. I thought I did and got that code after cleaning it, went back in pushed the plug harder and heard it click and lock in place.

ishsgt

from what i read online, if you block the egr vacuum hose then it should stop the dpfe problem. It didn't work for me. latly it has seem to stop surging so much but it sometimes dies down or bucks alittle bit. especialy when i hold the brake and put it in drive

tomtom660

I bought my truck in '10. Since the day I had it I had always got the P0171, P0174, P1131, and P1151 codes. It also would surge and occasionally stall. The brake pedal had a fade due to vacuum. After I brought the truck I took it to a reputable mechanic and was told it was a bad valve and not worth fixing.
Forward 13 years later and I started searching sites like this. I checked the EGR, replaced the severely altered PCV hose and check the valve.
I eventually stumbled onto a YouTube video. The guy had heard of a notice from Ford about the isolater bolts and plenum gasket in the intake.
While having other work performed I had these replaced.
The truck has never run better. No more surge. No more stalls. No more check engine. No more brake fade.