adam3797

95 f150 4.9l straight 6 5 speed rough idle stalls in neutral and when going into first. on the highway engine tries cutting off and bucks the whole truck around. replaced EGR valve and VSS. i unplugged vss on rear differential and it works fine, but that takes away the spedometer and ABS and all that good stuff. good fuel filter and full ignition tune up. i know my cat converter is clogged because i can hold my hand up to the tailpipe and its not blowing hard, but didnt think itd do this to the truck.
Any response is appreciated.

Aktech

See if there r any codes.

zoom zoom

Yea a catalytic converter could do that! Put a couple self tapping screws in the pipe in front of the cat and take them back out, it will be loud, but if the problem goes awaY you know what's up. Just stick the self tappers back in the pipe and leave em there when your done..

adam3797

which cat? i believe i have 2. unless one is a resonator

adam3797

this is the code i got


334

X

X

X

DPFE or EVP circuit above the closed limit of 0.67 volts.

Aktech

334=egr closed valve voltage high. Did u not get code 111?

adam3797

no 111 code. guy at oreilys sprayed down the lines with carb cleaner and no leaks. he also tested battery and said it was bad but i dont think its causing these problems. ive been wrong before. he also said knock on the cat converter (not too hard so i dont dent it) to break some of the clog up in there.
UPDATE: i also noticed that on my instrument cluster area it has the "4x4" symbol. mines a 4x2 did the previous owner replace it and could be causing these problems? also i really think the VSS has something to do with my issues since when i unplug it the trucks fine.

Aktech

Clean the egr. I'm not sure if 334 could be a is or was code. Someone should chime in.

adam3797

completely new 120$ Egr valve and sensor from oreilys. nothing

sdmartin65

Try unplugging the anti lock, its behind the glove box.