Contour Enthusiasts Group Archives Forums General Troubleshooting P0402 EGR Flow exsessive at idle?? how to fix

About 3-4 weeks ago i got a check engine so we scanned it and it was code P0402 EGR flow excessive at idle.
So we removed the EGR and cleaned it to make sure there wasn't any carbon that was keeping the valve open, so it was fine for about a week or so, and then i got the check engine again, giving the same code.
This time we checked the EGR solenoid. we remove the sponge filter in the solenoid and cleaned it.

it was good for a week then the Check engine light is back with the same code.

any other idea on how to fix this...i did a search and it seems that we covered all the bases...cleaning EGR and solenoid filter.

my SVT only has 37000 miles, so i don't think the EGR would have gone bad??

any ideas??

Just curious, how did you do this and what condition was filter?

Not sure I can help, but the EGR vacuum solenoid only involved to open EGR valve (on the presumption solenoid is not stuck open then it wouldn't be the culprit). You could pull off vacuum hose from top of EGR valve as a check.
The pressure transducer could be culprit if EGR valve is confirmed OK by your cleaning. Did you connect EGR vave to vacuum hose or pump before re-installing to see if it operated correctly?

p.s. I have presumed you reset PCM after each item.

to check the solenoid filter you just open the EGR solenoid and there is a sponge type filter sitting in there. It looked fine(almost brand new looking) to me, but we clean it anyway

we did check the EGR with a hand pump to see if it was working, and we did reset the PCM

how do you check the pressure transducer? I'll probably try that next, since i'm out of ideas to fix the problem.

The funny thing is that it says the problem is at idle but it doesn't seem to be acting funny at all. has normal steady idle (around 650k) and doesn't sound different at idle either.

I can only suggest a search on this site of p0402 code and see what turns up (or alternately DPFE)

I looked briefly and found this, perhaps of interest:
http://www.asashop.org/autoinc/dec97/egr.htm

I'm thinking i might just replace the EGR($55), but it just seems strange to me that it went bad with only 37,000 miles.

thanks for the help.
If anyone else has any ideas let me know.

Other than the simple things (pinched vacuum lines or electrical shorts), it looks to me that it is one of 3 things: EGR valve stuck open, DPFE sensor damaged, or EGR vacuum regulator solenoid. If you have access to a good OBD-II scanner (that can read DPFE voltage values for instance), I can give you the step by step diagnostics from the Service Manual. Otherwise, I'd start with the cheapest item first of the 3 I listed, once you have verifies that it isn't ne of the simple causes.

This must be the day for P0402, earlier today on the way back from Illinois, 500 mile trip, filled up on the Indiana Toll road and the CEL just happened to catch my eye. Duratec V-6 98 Mystique LS 39K miles. built 07/97
Must have came on after the fill up? Wasn't on before. Just used my laptop ALex's software, P0402 EGR flow excessive detected. Mine says nothing about idle? I also have under "TEST" $41 EGRDNHDIS Fail?
I've seen under search Bob Blayock last summer with a Zetec had the samething?
Just done visual so far nothing there, I'll jump into removing the EGR , since I did run some carbon remover Texaco's "synthetic fuel system cleaner" on the first tank on the way out last Thursday.
Whatever it's problem I may not fix it, ran the best it ever has just over 30mpg @ 70-80 mph.
I'll do some digging in the Mitchell's manual at our library and see if I can get into my head the
EGR's plumbing between all the components DPFE, solenoid, cats etc.
Paul

PA 3L SVT
Is this possible it detected it once and set the light or it happened "X' times then sets the light? Is this one of thoseCEL's that after "X" driving cycles it will reset?

Thanks
Paul
I only have P 0402.
Interesting article of course our cars don't use an EVR but what ever these EGR systems with OBD II look to be more problematic
than the earlier ones. If someone could just come up with a way to keep the carbon build up at bay?

I believe that this code is stored if it occurs for 10 seconds on two out of three drive cycles.

I believe that CELs are reset if they don't occur for 40 drive cycles.

Everytime (4) I've gotten that code, I've had to replace the DPFE sensor.
I'm on my 5th now. Kinda sucks but warranty is good for something.