need help with dtc codes

[polejockey65]

Hello to all and happy Thanksgiving.
I keep geting DTC code P0251,P0404, P0406.
I get the code on a normal start up in the morning has not been cold though here in Florida
I just replaced the harmonic balencer and the puley Today.
Don't know if this matters.
Any help would be a great favor
Thanks
Brian

[DmaxMaverick]

Happy Thanksgiving to you, too.

P0251 "Injection Pump Fuel Metering Control A"

P0404 "Exhaust Gas Recirculation Control Circuit Range/Performance"

P0406 "Exhaust Gas Recirculation Sensor A Circuit High"


This is a 2500LD (7200 GVWR), correct?
Check your grounds and connectors first. Could be a vacuum or vac switch/valve problem as well. Good luck!

[polejockey65]

Dmaxmaverick,
I just replaced the vac pump last week and found that the noise was the harmonic balencer well the pully so i replaced them both Yesterday. Still geting the codes. Two weeks or so ago both batteries went out , repaced them also
what are you referring to "vac Switch?" The thing with the green dot??
I replaced that 2 or so years ago when i bought an FSD Cooler from Kennedy Diesel .. Could it be bad again?
Thanks
Brian

[DmaxMaverick]

Switches/valves of any kind don't have a specific lifespan. Some last forever, others are bad out of the box and fail in a week. Your vacuum system controls the EGR and boost/wastegate systems. A bad switch on either system can dump vacuum, causing problems with the other system as well. You may have a vacuum leak somewhere causing the whole issue. Either eliminate the EGR system (temporarily for diagnostic purposes:)), or get it operating correctly, clear the codes, then address the P0251.

Have you cleared the codes, to see them return? Or, are they just persistently there? If they don't get cleared, they will remain in memory for a long time, even if you correct the problem.

[polejockey65]

Hello again,
I ordered a new vacuum hose ruber to the plastic one and a newwaste gate seleniod hard to find parts though for my truck.went to the stealer will be in on Tuesday Reset the codes and after driving for 30 minutes i got the engine light with the same codes.
Hope these parts work.if not I'll be back
Brian

[DmaxMaverick]

Best of luck to you. (sometimes it helps, and we can use all the help we can get!)

[polejockey65]

I have replaced the vac harness, seleniod, vac pump hose, vac pump, harmonick balencer and the pulley.
I drove yesterday about 90 miles or so and with no codes and the truck feels like i just bought it . outstanding would be the best word for describing it. now i need to try and get the pump retimed
Thanks
Brian

[polejockey65]

My joy was short lived i got the same three codes back, whats the next step and how if i wanted to disable the EGR

[polejockey65]

Hello to all
I have a question, i have replaced all 3 seleniods, vac pump, hoses and harness still have the same codes. they come and go day by day. i ordered a new EGR valve but a mech. friend says i need to pull the upper intake and clean the soot out before installing the new EGR valve. Does this need tobe done?? is there anything else i can do or check before i get any futher. any help would be great. please help i still have these three codes: DTC code P0251, P0404, P0406
Thanks

[polejockey65]

hello to all
sorry to take so long to get back to you all. i have not had a code i two weeks or so. I have been real busy with the family/work but when i replaced the last of the seloinds the white dot was the problem. the parts guy canceled the egr valve since it was back order anyway. the trucks runs like it was new again. I have replaced a lot of things recently should i have the timing re checked since the harmonic balencer and pulley went bad right in the middle of everything else that was going bad. Should I check for the P0251 code will this code stay in? or will i get the SES light if its still a problem
Thanks