[DayOff]

Before ya'll start yelling about the search command, I've read every thing on here about DPFE, EGR, P0402, P0401, and nothing answer me question satisfactorily(sp).

So here it is. I had my codes scanned recently and came up with a P0402 EGR flow something-or-other(yes, that's exactly what it said). Tested the EGR, seems fine. I tested it by applying vacuum to the top of it and the engine shuddered. This leads me to believe the problem is my DPFE.

Is there a test for this? Or, do we just have to buy a new one and replace it?

Also, the car seems to idle a little rough in drive at about 600 RPM. It also seems a bit low on gas mileage and acceleration.

BTW, it's a 98 Sable GS.

Thanks

 

[Bob Gervais]

Here's the DPFE test:

l Disconnect pressure hoses at D.P.F. EGR sensor.

l Connect a hand vacuum pump to the downstream connection at sensor (intake manifold side of sensor or the smaller diameter pickup tube).

l Key on, engine off.

l Access DPFEGR PID with a scan tool and note PID value.

l Apply 27 to 30 kPa (8 to 9 in-Hg) vacuum to the D.P.F. EGR sensor and hold for a few seconds.

l Quickly release vacuum.

-- The DPFEGR PID voltage must be between 0.2 and 1.3 volt with the key on and no vacuum applied.

-- The DPFEGR PID voltage must increase to greater than 4.0 volts with the vacuum applied.

-- The DPFEGR PID must drop to less than 1.5 volts in less than 3 seconds when vacuum is released.

l Does the DPFEGR PID voltage indicate a fault in the D.P.F. EGR sensor?

Yes
REPLACE damaged D.P.F. EGR sensor. RESTORE vehicle. COMPLETE PCM Reset to clear DTCs. RERUN «Quick Test».

No
RECONNECT D.P.F. EGR sensor. GO to «HE24».

 

[DayOff]

Okay Bob...All you had to say was just replace it.

 

[Bob Gervais]

Originally posted by DayOff@Jul 10 2004, 07:37 AM
Okay Bob...All you had to say was just replace it.

I didn't write all that! It's a copy and paste from the service CD. I figgered you wanted to know how to test it....

You're right though, with what we know about this code, and the cost of the part, it's worth the risk to just throw another one on there. :thumb:

 

[DayOff]

I figgered you wanted to know how to test it....

I did wanna know how to test it....simply...at my house....without buying all kinds of expensive machines.

But thanks for the cut and paste.

 

[Nidan]

Hey guys. I'm a mechanic at a Ford dealer, and those DPFE sensors are very common for failing. Easier test to check when you have those codes - if you have the equipment, leave the sensor hooked up as normal. Watch the DPFE PID - at idle it should be around 1 volt, give or take. Hook up a vacuum pump to the EGR valve, and open it. As the engine starts to stumble, you should notice the dpfe voltage increase. Bring the engine speed up some so it doesn't stall, and increase opening the egr valve until it's open all the way... your dpfe voltage should hit 4 volts or a lil more. If it doesn't change, or the voltage is too high with the egr valve closed, or too low with it open, replace the sensor. As i said, they are very common, and i've done a couple on my own vehicles.