Well, I got this 98 4.2 in June. The check engine light is on. I replace 2 oxygen sensores, and put in new plugs, then reset the computer. Within an hour the light is back on. I have a few Questions:

1. Is the maf those little tiny wires inside the part where the air filter connects?

2. Is the throttle body elbow an issue on the 4.2 like it can be on the 4.6? I assume that is the tube from the egr to the manifold?

I can't figure it out.

 

1.) correct...you can clean those with some electronics cleaner,but I would'nt recommend trying to clean them with a Q-tip or any thing else...just remove the MAF and spray both sides and let it dry...2.)it's from the PVC to the area behind the throttle body right where the hose makes a 90 it cracks and starts leaking there...the EGR symptoms are due to the return ports clogging up with carbon deposits...search the items and you'll see posts on them

 

I have a 97 4.6 and the check engine light was very hard to remedy. I tried plugs, egr valve, etc.... I had several mechanics, including Ford, to try and find problem. Finally, replace the DPFE sensor. Took care of check engine light. Cost approx. $75 I think.

 

This maybe a silly question, but what was the code ?

I did not see a code number, and you seem to be replaceing stuff that might not have anything to do with it.

While the EGR ports being clogged can lead to a code set, as well as O2 sensors or cracked vac lines, a gas cap not tightened ( or filling the truck with the engine running, or an oil dipstick not pushed all the way in can also cause a code.

Just curious if you have the code number, I can look up this in the Ford service manual and give the recomended list of things to look at, per Ford.

Just an offer.

 

Sorry to butt in here but what exactly is a DPFE sensor???

 

The code was P0401 EGR insufficient flow detected. As for what DPFE sensor means, Differential pressure feedback system--Emmissions.