When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
My son has a 95 Ranger with the small 4 cyl engine and is getting an error code indicating the EGR flow is insufficient. I forget the code number but we have replaced the EGR valve and the sensor. The hoses look ok and are connected properly. He gets the code after about 70 miles of driving. My question is, what controls the EGR, the computer? Is there any other parts that could be the culprit for this problem other than the computer? Our next step is to blow out the sense lines, maybe they are plugged? Any assistance is appreciated.
As you say you've replaced the EGR valve & sensor,( I assume you mean the DPFE sensor), you might then look to & check the VSV = Vacuum Switching Valve, as it recieves directions via a pulsing voltage signal from the computer, to directly switch vacuum pulses to operate the EGR valve. So if the VSV is acting out, so will the EGR valve.
Be sure to check it's electrial connctor & vacuum lines.
oops recently had a problem with her VSV that was the cause of her P0401 code & like you, she had replaced her EGR & DPFE without success. She was also having some mid range driveability problems.