Under the hood
take it in
$30
P0401 "egr insufficient flow" can indicate many things, including: 1-vacuum line plugged or leaking 2-pipe from exhaust to egr valve plugged 3-pipe to vacuum modulator valve from egr valve plugged 4-passages at egr are plugged 5-bad egr valve 6-bad EGR VACUUM MODULATOR VALVE I tried cleaning egr modulator valve, (beside/above egr)removed and tested egr vacuum & movement, inspected and cleaned all vacuum lines openings and pipes. All above did not work. I replaced the egr vacuum modulator valve. Light went out without a reset in about 30 miles of driving. Not sure if this valve can be cleaned. Retails for $69.US
It is either a bad fuel injector or a problem with a valve in that cylinder
5W-30 , according to the 2000 Ford Ranger Owner Guide
the egr valve is sticking open and causing the motor to surge replace the egr valve and the problem will be solved
For a 1995 Ford Ranger : ( 5W-30 is the PREFERRED oil ) * 2.3 / 3.0 / 4.0
10/30 --------------------------------------------------------------------------------- According to the 1996 Ford Ranger owners manual ( 5 W 30 is the PREFERRED oil )
5W-30
( 5W-30 ) is the preferred oil , according to the 1997 Ford Ranger Owner Guide
i had the same problem when i smogged my truck and it is probaly two things the extenison connector to a little sensor on the passenger side fender wall next to the fire wall. just follow the vacuum lines from the egr valve. all it is an 2 inche extenison to a connector that can go bad from time to time and you really don't need it. just plug the sensor back in. the egr position valve sensor. the little plastic thing connect to the outside of the egr valve on the of the enginge to the rear. this part will run you around $30 - $45 dollars
The 1998 Ford Ranger Owner Guide shows ( 5W-30 ) for the 2.5 / 3.0 and 4.0 engines