My 97 F150 threw a P0302 and P0401 the other day, I traced the miss fire to a loose injector plug. I reset the codes last weekend, I got in the truck and went to the Dump and to town to pick some stuff up. It threw the EGR code again, so this morning I did a little checking on the EGR I cranked the truck and disconnected the FPR vacuum line and hooked it to the EGR valve and the truck died down but didn't completely die. Now the green line that went to the EGR valve felt like it had a slight bit of pressure coming from it. Is this normal? I did pull the white feed line from the EGR Regulator and it had good vacuum. The regulator also makes a humming sound when you cut the truck off. Ill be pulling the alternator this weekend due to it going out last night, while I'm in there if Ive got to pull the throttle body id rather do it while I'm elbow deep in it. So does it sound more like a Clogged Throttle body or a Faulty sensor?

Thanks for any help or suggestions

 

Not a clogged throttle body if the motor sees the exhaust test you did and caused rough idle.
There should be no 'significant' vacuum to the EGR at idle.
It the system should not make any noises.
I would clean the EVR to be sure it's not sticking open any amount because the EGR once opened has to 'bleed' the vacuum off through the open port of the EVR at it's non operated position (third port) open to air.
If the EVR is not free to work it can cause a 401 test failure.
Cleaning it will eliminate it as a possible cause, otherwise it could be the DPFE sensor or a hose issue.
Good luck..

 

How do you go about cleaning the ERV? Any specific spray or anything? I figured it was.nt in the throttle body since it died down at idle with vacuum but wanted to made sure

 

Remove the device.
Remove the round cap.
There you will find a filter.
Use throttle body spray can cleaner inside the ports until it runs out clean.
Wash out the filter and reassemble, re install.
.
The filter blocks dirt from going back to the EGR. This is the third port.
If it gets plugged the EGR will be slow to release, cause some noises after shutdown and possible drivability issues.
Good luck.

 

Okay thanks! I'll be working on it this weekend I'll post up after I see what it all looks like inside.