Thank you for any help. I'm a newbie here..
2001 Ranger 2.5 - 4 banger has 'all of the sudden' developed a severe rough idle, throwing code 1401, I have changed the EGR valve, Idle control valve and the EGR High Pressure Switch. I can NOT find a vacuum leak either. Problem remains. What do check or change next ? Could it be as simple as bad gas ????

Please please please help :(

Burt

 

Welcome to the forum

2001 2.5l SOHC dual spark plug Lima engine

P1401 Diff Pressure Feedback EGR Circuit High Input

DPFE sensors last from 1 to 10 years depends on humidity in the air/exhaust

Read here: https://www.ranger-forums.com/2-3l-2...t-code-152240/

Check the 2 hoses on DPFE sensor, one hose is larger that the other so there is a right way and wrong way to hook them up, at both ends
Blow thru both, engine off, lol, make sure they are clear

With engine idling unhook the vacuum hose on the EGR valve, see if engine runs smoother, if so then EGR modulator is leaking, or vacuum hoses are connected wrong
There should be NO VACUUM at the EGR valve at idle, EGR system is only used when driving and engine is under a load
With Vacuum hose unplugged put finger on the end to see if there is vacuum present, should not be
If so then follow that hose back to the Modulator

 

Question - how long after replacing the DPFE should it take to correct the issue ? Immediately ?

After I put the new one on I only let it run about 1 minute and said - well that did not help. Does it take a few minutes to reset ??

Thank you so much !

 

Did you Clear the codes?
If so then it shouldn't set a code again unless the issue was still present

If you didn't clear the code then it can stay until computer has retested that system a few times, now long that takes can be a few hours to a few days

If you unhook the Negative battery cable for 5min then reconnect it, that will clear codes in memory

Clear the codes
Unhook the vacuum hose from EGR Valve and plug the end of that hose with a screw/bolt or tape
Start engine
See if code comes back, you can drive that way as needed
If not then problem is with the EGR modulator
If code comes back then problem is in the DPFE sensor or its wiring, or even a computer problem

 

1401 code remains. My question was after replacing the DPFE should I have let it run more than 1 minute to see if the idle improved or should it have immediately improved if the DPFE was the issue ? I assumed it would show idle immediate improvement if the DPFE was bad

Thank you

 

The DPFE sensor has nothing to do with idle, it just monitors EGR valves open and closed status
The Code P1401 Diff Pressure Feedback EGR Circuit High Input
Can mean the EGR valve is OPEN when it should be closed, and that would effect idle, exhaust gases are only allowed in the intake when engine is under load, driving, and only after full warm up
Exhaust gases in the intake at idle will cause poor idle

So disconnect the EGR valves Vacuum hose and see if idle is better, if so then EGR modulator is not working and that caused DPFE sensor to set the P1401 code