Am getting P0401 code got approx. 20 in vac.at egr have replace both egr solenoids . Black smoke intermittent under acceleration . Any help appreciated

I did a key word search for EGR, this was a recent good one.


www.dieselplace.com/forum/forum_posts.asp?TID=14072&KW=EGR (http://www.dieselplace.com/forum/forum_posts.asp?TID=14072&KW=EGR)





Edited by: quantum mechanic

I get black smoke on a sporatic basis ,about 75 percent of time under aceleration . Am at a loss as to what might be causing it . When I unhook and plug egr vac line occasionally engine will just shut down .


Suspected PMD so I remote mounted it .Haven't tried to plug egr since .

What year model truck? Have you checked the hose to your MAP sensor?

98 K1500 with banks stinger exhaust downpipe back . 373 rear , 140000 mi. I am starting to suspect some type of sensor is there any other than MAP .

The EGR makes everything complicated but A leaky vacuum hose can cause the black smoke on acceleration.

I think I have or had a couple of things go bad at the same time like the pmd , I've got right at 20 in vac at egr but haven't had time to really check everything on vac system

I think what TDG ment was Baro sensor. The second solenoid in the bank is the EGR vent and it is tied to the Baro on the firewall and the EGR via vacuum hoses. Any leaks and the PCM can't figure the EGR cycle correctly.


Turbo's vacuum line should have ~15 " hg at idle.

Oops, caught me there QM, yeah, I meant the BARO, my mistake. A leak in this line will cause a higher reading than there should be, causing the ECM to send more vacuum to the EGR making it open too much and dump exaust into the intake. Just remove the Tee to the EGR valve, making it stay closed all the time and run the existing hose or a new one to the BARO and you shouldn't have any more EGR problems.