Contour Enthusiasts Group Archives Forums General Troubleshooting CEL Code P0401- EGR Valve flow insufficient

What would cause this code?
It just means i need a new EGR valve correct?
Would this explain the slightly rougher ide i've noticed?

*edit* How hard is it to replace the EGR Valve?

since the idle of the car has become rough i would agree with the egr valve needing replacement

to test you need to apply a vacuum to the valve, it idle gets worse then the valve is fine, if no change then the valve is bad

if it tests fine then i would check the DPFE sensor but this doesn't sound like the case

I am not sure how hard the egr valve is to change, if I am thinking of the right thing it is right on the top right corner of the intake manifold

The EGR valve rarely fails compared to the more commn faults of clogged EGR passages or a fault with the DPFE sensor.

To test the EGR valve and passages, just connect a short length of vacuum hose to the EGR valve and suck on it while the engine is idling. If there is no change in idle speed, then you know which half to focus on.

With a rough idle, you likely have multiple problems. For the EGR system to cause this particular symptom, it would have to be jammed partially open. This is possible, but not a common failure. Check for it anyway.

Steve

Remove the throttle body from the intake manifold and scrape and spray off all the crud. Both of mine needed this and the light stays off after it.

I tried all the "other" fixes only to find that my EGR valve was bad. So, although all the other suggestions are helpful, it very well could be the EGR valve. I also have a '99 CSVT. An inspection revealed pinholes developing in the diaphram.

It's quite easy to replace, loosen the large tube nut, remove two bolts, remove gasket.

Check the small hoses that go from the EGR tube to the DPFE. Is your DPFE metal of plastic?
Possible causes:

-- Fault in vacuum supply to EGR vacuum regulator solenoid.

-- EGR valve stuck closed or iced.

-- EGR valve diaphragm leaks.

-- EGR valve or flow path restricted.

-- EGR vacuum hose off, plugged or leaks.

-- VPWR circuit open to EGR vacuum regulator solenoid.

-- EGRVR circuit to PCM open.

-- EGRVR circuit to PCM shorted to PWR.

-- Differential pressure feedback EGR (D.P.F. EGR) sensor pressure hoses both connected improperly.

-- D.P.F. EGR sensor pressure hoses reversed.

-- D.P.F. EGR sensor VREF circuit open.

-- Downstream pressure hose off.

-- Downstream pressure hose plugged.

-- Damaged orifice tube assembly.

-- Damaged EGR vacuum regulator solenoid.

-- Damaged D.P.F. EGR sensor.

-- Damaged PCM.

l Run KOER Self-Test.

l Key off.

l Was KOER DTC P1408 output?

Yes
The KOER Self-Test has detected an EGR fault that is currently present. GO to «HE71».

No
REMOVE and INSPECT the EGR valve and intake manifold EGR port for restriction. If OK, the fault that produced DTC P0401 is intermittent. GO to «HE90».

ALL this just from code 0401 insuffiecent and 0402 excessive flow.

1 The EGR vacuum regulator solenoid trace back the vacuum line from the EGR that is the solenoid and check the filter to see if it's plugged.
2 DPFE bad or hose issues.
3 Carbon plugged passages behind the manifold gasket on the Throttle body.
my 98 built (07/97) had a aluminium DPFE F48E-9J460-BB and was replaced with a plastic body F77Z-9J460-AB no problems for over a year and a half.
If you do pull the throttle body get a new gasket first.
Paul
If the hoses between the DPFE and the EGR tube are off possible Cats are starting to clog.

http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=v6maint&Number=337774&Forum=All_Forums&Words=14534&Match=Username&Searchpage=18&Limit=25&Old=allposts&Main=337774&Search=true#Post337774

The most common reason why you get that code under the check engine light. Easy fix.