Obd P0400

[studentjunk]

Anybody know what OBD colde P0400 means? My Dynoscan software indicates it's exhaust gas recirculation flow, but I don't have details. I did a few online searches, but couldn't find anything that was terribly helpful. All I gathered was that my emissions could be bad or it could lead to poor engine performance. However, my car has been running fine. I reset the code, and the check engine light hasn't come back on for at least 200 miles (it came on at the beginning of a 360 mile trip).

The only complaints that I have about the car haven't been worth fixing. The idle has been a little rough at red lights. This has been going on for years. Mechanics recommended changing spark plugs, but that hasn't helped. The other problem occured after the mechanics cleaned the fuel injection system in May. Ever since then, bad fumes have been coming through the vent unless I recirculate the air. I figured they had spilled oil or something during the job, but the smell always comes back when the vent is open. I only smell it when the car is going slowly, not on the highway. Maybe these problems are related to the P0400 code. Anybody know?

[davens]

The EGR valve is a known problem.
It will cause your bad idle as well.

It's easy enough to replace but the part is expensive

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[studentjunk]

If I ignore the problem, will it cause engine damage? Or should I just bite the bullet and go ahead and repair it.

The EGR valve is a known problem.
It will cause your bad idle as well.

It's easy enough to replace but the part is expensive

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[midnightblue97]

If I ignore the problem, will it cause engine damage? Or should I just bite the bullet and go ahead and repair it.

Wether it will cause engine damage or not, you should bite the bullet and get it fixed.

[davens]

It won't cause engine damage...the problem is that your check engine light will be on because of the EGR.
You get used to it being on. But then something catastrophic happens and the check engine light is triggered. Whoops, it's already on. And you're ignoring it because you think its the EGR valve. And you drive on down the road blissfully unaware that your engine is about to frag itself.

[Intruder]

...And you drive on down the road blissfully unaware that your engine is about to frag itself.

this makes me wonder...
I've had my CEL on for more than a year... breakdown is imminent (I hope not!!!)

[2young2retire]

Presently my '96 Protege' LX has 165,000+ miles on it and the CEL came on for the second time last month. Had the codes read at Autozone and they said it was EGR low flow. Had the EGR valve replace at about 80,000 miles by the dealer and it was expensive. When it indicated bad a second time I thought I had nothing to lose by taking it off and looking at it. Once removed it I move the diaphram and the valve moved freely. Pulled a vacuum on the diaphram and all was good. Found the outlet going to the sensing line plugged with carbon. Took a small drill bit and cleaned it out and checked it to be clean all the way through to the inside of the valve. I reset the CEL and replaced the valve. Been two weeks and almost 600 miles and no CEL. May want to try this trick before having the dealer replace it.