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P401 code


mercurymorris
11-15-2004, 11:05 PM
I have gotten a P401 code (EGR insufficient flow) on a 1998 Lumina. I removed the EGR valve and found the springed actuator was sticking, so I replaced the EGR valve. The code comes back within two drive cycles of clearing.
The car sometimes starts rough but runs ok after a few seconds. The mileage is 98,000. Any ideas?

Thanks

cadgear
11-16-2004, 03:11 AM
Just fixed this on my neighbor's 96 cutlass, about 80k mileage. The passage from the valve to the intake is more than likely clogged, and its nothing a guitar string/coathanger and a shot of carb cleaner can't fix. Take you about an hour, be sure you have some rags and a shop vac handy. Fortunately, this fix costs nothing but some time, and it wouldn't hurt to clean it out, so even if it is something else (MAP sensor, in this case) you didn't spend any moolah on it.

richtazz
11-16-2004, 03:50 PM
I agree with Cad, sounds like a clogged egr passage.

mercurymorris
11-16-2004, 03:58 PM
Just fixed this on my neighbor's 96 cutlass, about 80k mileage. The passage from the valve to the intake is more than likely clogged, and its nothing a guitar string/coathanger and a shot of carb cleaner can't fix. Take you about an hour, be sure you have some rags and a shop vac handy. Fortunately, this fix costs nothing but some time, and it wouldn't hurt to clean it out, so even if it is something else (MAP sensor, in this case) you didn't spend any moolah on it.
Thanks for the advice. I'll try this ASAP. Throwing parts at a problem is expensive. $180.00 for the EGR valve.
Hope this works.
Thanks

cadgear
11-16-2004, 04:25 PM
An additional note, you'll want an assistiant or something to block the throttle open. The passage is about an inch or two inside on the right wall of the intake..you can probably feel the hard crusty crap built up on the side with your finger. Sounds strange but be careful, it is sharp and can cut you (the buildup, that is)

mercurymorris
01-09-2005, 03:48 PM
I have cleaned all the passages I can get to and no luck. I next replaced the MAP sensor and cleared the P401 code and the next time I started the car the code came back. Anymore suggestions or is it time for a professional?

Thanks

cadgear
01-09-2005, 06:00 PM
Start thinking about a $200 EGR valve then, if all the passages are cleaned and the wiring is OK.

mercurymorris
01-09-2005, 10:05 PM
Thanks,
But I have replaced the EGR valve first and the code came back. The MAP sensor was the second part and no luck.

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