I have a 1998 F-150 4.6 v -8, auto. with about 110,000 miles. I changed the spark plugs & wires about 6 months ago & replaced the EGR vale about 2 months ago. Everytime I start the truck when it's been sitting for awhile (in the morning, after work, etc) it idles real rough for about 10 seconds to 1 minute. After that it seems to run & idle fine. The check engine light comes on. I checked the code and it showed code # P 0401. I do have a Super Chips 87 octane tune in it & the Gotts air intake mod. Can anyone tell me whats going on & how to correct it. Thanks Chief Mike.

 

Get a piece of vaccum hose and literally suck on the EGR port while your truck is idling to see if it bogs down. If your EGR is working properly then it should bog down your engine almost to the point of stalling out. If your engine does not fluctuate in RPM's then you need to take the intake off where the EGR attaches and clean the ports. They tend to clog up pretty bad.. mine did.

They should look like this(well cleaner, but you get the idea )


I would also look into the DPFE sensor.. it is located between the EGR and EVR vacuum solenoid.. it has the two tubes that go into it. You can tell fairly easily by flipping it over and looking inside where the tubes go if there is alot of carbon buildup. If it looks really nasty then it most likely does not work any longer, and that can pull a 401. BTW, you need to make sure that you are replacing any and all of your parts with MOTOCRAFT only.. you will spend twice the amount replacing the cheap(non-motocraft) parts when they go out. Trust me.. I have tried this. Should you need a new EGR or what have you.. shell out the money for the motocraft part from the get go.

 

Yep, sounds good to me. If you don't understand, just post up.

 

I think I am going to try this cleaning process. I tried the suction hose on the egr port & nothing. The rpm did not drop. Is this the part where the throttle body mounts also? How do you remove the big hose in the back? It looks like 4 bolts hold it down. Is that correct? Do parts houses carry all the gaskets to put it back together? Thanks. Chief Mike.