After getting the "insufficient EGR flow" code I removed and cleaned my throttle body, elbow and EGR housing. Still had code, bought and installed DPFE sensor and code returned... What next? '97 5.4 74,00 miles. Could the header or tubing to the sensor be obstructed? Do I have the right sensor? (old# F48E-9J460-BB, new#F77Z-9J460-AB). Anybody have the troubleshooting tree for this code? Smog check due in 2 months!

 

Could be the manifold to EGR tube clogged up. Have you tried adding vacuum to the egr while idling to see if it actually bogs like it should?

 

I'll try that... I should have done that before the DPFE, I ignored my mantra "do the cheap stuff first"! I'll post back with the result.

 

I was finally able to work on the truck again today, please bear with me. I used a hand vacuum pump to test the EGR valve today, pumping from 0" of vac. I wasn't able to get the truck to stall and was not able to build vacuum no matter how fast I pumped... shouldn't the EGR valve hold vacuum? I then valved off the pump, stored vacuum and then released the vacuum to the valve... at 30" of vacuum it opened the valve enough to stall the truck but after opening the EGR valve the vacuum quickly bled off to 0". I traced the vacuum lines and found that from the manifold the main line goes to a tank inside the pass. side fender then splits to the EGR control mounted on the manifold and an AC control valve mounted in the drivers side firewall. The AC works fine so I assume the tank and lines are OK and this plus the troubles I had getting the truck to stall mean a bad EGR valve... sound right? I asked about the vac tank inside the pass. fender because I had an accident and the fender was replaced so I saw it at that time, I thought that maybe the tank was cracked during the wreck because this code showed up after the accident... does anybody know what amount of vacuum this tank is supposed to hold and at what level of vacuum the EGR is supposed to open? What does an EGR valve cost and how do I remove the tube from the ex. manifold to the EGR without destroying it? :-) I'm also wondering about the control mounted to the throttle body that sends vacuum to the EGR valve, it has a 2 wire plug and the vac. line from the tank (white) goes to it and sends vac. to the EGR through a second (green) line. How do I test this and what is it called? Or am I barking up the wrong tree?

 

Anyone? :-)

 

Anyone? :-)

 

Did you apply the vacuum directly to the valve or thru the factory vacuum line?

 

Thanks for the reply LX, Directly to the valve... I was puzzled because I thought it should hold vac. till I read somewhere that there are valves that must see exhaust backpressure before they will hold vac. Do you know if Ford uses such a valve? Thanks again.

 

I've never seen that on a Ford. The EGR valve should hold vacuum.

 

Thanks Dave for the reply! Looks like I'll be replacing the EGR then... Any tips on removing the exhaust tube connection at the EGR without trashing it? I'd like to keep that tube intact because the connection at the exhaust manifold looks really scary!

 

Lots of penetrating oil the night before you start.
Usually they come off easier than they look like they will.

 

Replced the EGR yesterday... reset and so far no codes... Had it out for a combined 20+miles of combined city/hwy. EGR was easy to swap, it would have been 20 minute job but when the nut let go I smashed the crap out of my *new* DPFE sensor and had to repair the housing on it! Note to others: remove the DPFE before going after that big nut on the EGR, they are very close to one another! If I still had on the old one with the metal housing it wouldn't have even scratched it!