After replacing the power steering pump and hose a couple days ago, I was greeted with an MIL during a WOT test drive
PO401 (Insufficient EGR Flow)
Cleared it a few times, but it always came back after a 3rd cycle, so sumthin was definitely kaput
Checked the EGR Valve and it tested fine.
Checked the modulator and although it passed the FSM's test fine, it didn't hold pressure when I blew into the bottom port (still not sure why the FSM doesn't have this test listed as it's more straight forward)
Here's a link to my original EGR thread that has since been closed:
https://forum.ih8mud.com/80-series-...er-dreaded-401-thread-few-diag-questions.html
New modulator came in today and although the old one still looked new on the outside, after cracking it open, you could clearly see the diaphragm torn
Didn't bother checking the VSV, but so far, no more MIL, even after 4 drive cycles
PO401 (Insufficient EGR Flow)
Cleared it a few times, but it always came back after a 3rd cycle, so sumthin was definitely kaput
Checked the EGR Valve and it tested fine.
Checked the modulator and although it passed the FSM's test fine, it didn't hold pressure when I blew into the bottom port (still not sure why the FSM doesn't have this test listed as it's more straight forward)
Here's a link to my original EGR thread that has since been closed:
https://forum.ih8mud.com/80-series-...er-dreaded-401-thread-few-diag-questions.html
New modulator came in today and although the old one still looked new on the outside, after cracking it open, you could clearly see the diaphragm torn
Didn't bother checking the VSV, but so far, no more MIL, even after 4 drive cycles