nickb

I have a 1997 4.2 f150. I had an insufficient egr flow code and after some research I changed the DPFE sensor with one from Ford. I cleared the code and a day later it came back.

I checked the egr valve and it is working properly. I have taken off the throttle body and cleaned the EGR ports. I even took off the upper and lower intake manifold to make sure the egr ports are clean.

Is there anything else that can throw this code that I should be looking at? How does vacuum work with the egr? Is it by rpm? I'm getting 0 vacuum at idle and at higher rpm's.

Thanks,
Nick B.

torkum

What was the exact code number you got?

nickb

p0402 excessive egr (not insufficient)
&
p1401

nickb

Anyone?

LOHfootball53

I got the P1401 and I replaced the DPFE sensor and everything went back to normal.

torkum

Excessive would lead me to check to see if the EGR is stuck open but you said it checked out. The next part I would check would be the condition of the tube going to the EGR. Could be rusted out at the exhaust manifold end.

nickb

OK. I checked the egr tube to the exhaust pipe and it is in good condition( cosmetically, could it be clogged?).

I thought the EGR might be stuck open too but with the a little bit of vacuum the truck idles rough and with more vacuum it shuts off.

torkum

One question, did you check the wiring going to the DPFE to make sure the volts are correct? If the volts are ok the code may require a reflash from the dealer.

torkum

Another thought, do you have a aftermarket air filter like a K&N?

nickb

Voltage was at 4.9V. No aftermarket air filter. What do you mean by reflashed? By the way, thanks for all your help.