Mechanics

ENGINE HESITATION

1999 Ford F-150 • V8 2WD Automatic • 248,000 miles

When driving the engine hesitation and miss and the engine service light is on it have a code P0401 will that be a EGR valve if it is where is the EGR valve located on the engine is it hard to replace?
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Joe1953
February 28, 2014.




Here is a tip

Had a 99 Cougar with a 2.5 with P0401, low flow EGR. I first tested the EGR with a hand held vacuum pump during idle. Not only did the DPFE reading on the scanner not move but there was no difference in idle speed or quality. Removed the EGR to check operation, open and closed good. But could not blow air through the passage on the intake manifold. Don't waste your time trying to clean it with a wire or blow gun, just remove the throttle body, it's all plugged up right there. Now test it again. The DPFE was reading.42 volts at idle, not high enough, should be about 1.1 volts, so now replace DPFE. Test again with the vacuum pump at idle, all works good now. If the DPFE has been out of commission for a while the ECM won't bother with any EGR operations, I think this is what gets the passage plugged.
Probably same with your truck
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Hmac300
Mar 1, 2014.
What does DPFE mean? Where is the EGR located on the engine? Are you saying the throttle body is plugged up is it easy to remove?

Tiny
Joe1953
Mar 1, 2014.
Dpfe is a sensor that operates the egr as you didn't give an engine size I couldn't tell you where it is but look towards the back. I think this is a little beyond your capabilities though and have a pro look at it or fix it. He can fix it cheaper and have it back quicker than you could

Hmac300
Mar 1, 2014.

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