EGR code check engine light

Asked by Apr 22, 2017 at 11:08 AM about the 1998 Ford F-150 Lariat 4WD LB

Question type: Maintenance & Repair

I have a 98 f-150 4.6l 4wd. Have replaced egr, cleaned all areas of egr and
replaced sensor under egr. In addition replaced computer thinking one of the
banks was bad.
Trucks runs excellent  no rough idle or any other issues associated with an egr.
Could this be a witing issue. The shop I have taken my vehicle too has been
excellent trying to solve this issue but still have the issue and need an emission
test for my registration. Any help would be greatly appreciated, thanks

7 Answers


how many miles / hours do you have on it since your last repair ???

1 of 1 people found this helpful.

What code or codes are present? Sometimes an exhaust leak will trigger it. I see you replace the EGR and position sensor, is that right? There is a vacuum line hooked up the EGR, might be an issue with not enough vacuum to operate the valve, etc.

1 of 1 people found this helpful.

Code P0401 EGR insufficient flow". ??? takes up to 100 miles for the computer to sample enough times for it to determine it is ok and turn off the light. the DPFE was a common problem with Ford. Ford said this switch had been upgraded from the metal one to the plastic one. . VACUUM OK? HERES MORE INFO FOR YOU..GOOD LUCK...SHOULD BE A NICE FIX. the ports needs to be cleaned, AT THE EGR BASE 1.2 OR 3 HOLES HAVE TO BE CLEANED Cleaned it all up and put it back together. Problem solved. I replaced over $100 worth of parts and probably didn't have to change anything. So if somebody has had a cronic problem with the EGR code, clean up the trottle body

2 of 2 people found this helpful.

Kelly and Tom thanks for the input. Truck has about 195k on it. The shop has cleaned everything associated with throttle and egr system. Vac is good as well. As for 100 miles for enough sampling light clicks on in only 5-10 miles after reset. The shop has driven with computer hooked up and can watch it just drop out, they reset same thing. This was why new computer but after replacing same issue. I notice my muffler is starting to split at the seems would that cause an issue sith the egr? Again appreciate the responses thus far hopefully this info can better help in a fix.

Anyone have any experience with this issue? All new egr system in essence, vac good, computer replaced. Code comes back on 5-10 miles after reset. Really need to have this issue resolved. Thanks for any advice


is the exhaust clogged ..pluged up..oh boy

1 of 1 people found this helpful.

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