can someone please chime in on the above readings I got from my truck? I can't see how the EGR valve can bounce around that drastically but who knows...what about everything else?

 

Been so long since I had a functioning EGR valve that I can't comment on it, but it doesn't seem right. Please confirm exactly what that reading is (since it is in %, is it duty cycle?, is it the commanded value?).

Also, I would put the oil temp in *F to match the coolant (or vice versa).

 

Thanks Bis...Forscan says EGRVPA stands for EGR Valve Position Actual...with KOEO and at idle after being turned on, it reads 0% while after getting the engine to operating temps the %s increase....so to me the % corrolates to the % of the valve open at that particular moment which again I dont see how an EGR valve can go from completely open to completely closed, at the same
exact moment when the turbo is surging...This still could be a side
effect of the turbo surge though, or could be a cause of it, but no EGR trouble codes are present, just the PO299 Underboost

I just added in EGRVPD-EGR valve position desired into my dashboard so I will see how the 2 readings interact....I couldnt find EGR Valve commanded value but will look again under the OBD section...also added in Trans Fluid Temp and put the Oil Temp to *F! oops...

Anyone? Thanks guys

 

Is it possible that my EGR valve is bad and causing the turbo surging and giving me a PO299 Underboost engine light??I ask cause at Bismics request I added in the EGR Valve Commanded onto my dashboard on Forscan Lite and sure enough the EGR valve actual jumps all over the damn place while the EGR commanded steadily changes and rarely had a value of over 25% and thats at idle when both actual and commanded were close...
Something else I noticed is that the turbo surge is almost non existant when cruise control is on...not sure why that could be other than maybe the gas pedal is super sensitive and my right foot is shaky?! Or is there a logical explination for that? Also the VGT Solenoid % didn't jump all over the place with cruise on, while the EGR was all over the place with cruise on...In any event, here are some shots of my readings from Forscan...1 should be idling after a 20 mile drive, 1 should be full throttle and 1 should be going about 40mph
Tomorrow I am going to unplug the EGR valve and see what happens....I will be perplexed if the EGR does this same shenanigans




cruising



full throttle



idle after driving

 

Have you pulled the EGR valve out and inspected it yet? It has a really firm spring to keep it closed by default. If the spring inside is broke it may be opening by boost pressure.

 

Hey 87! Yes I did take out the EGR valve, cleaned and inspected it...it was pretty dirty but not as bad as some I have seen in photos and videos...still opened and closed smoothly...o rings were fine and I was cautious to avoid getting close to the top of the valve and messing it up...
what do you think about the turbo surging almost dissappearing with CC on? could my EGR valve be causing a turbo code as a result of a bad egr valve?

*Update* I was told by a guy that disconnected the EGR valve and drove his truck which happens to be the same exact truck I have with the same exact issues I am having...just to be clear I didnt unplug my EGR valve, this guy did...after getting truck to normal temps it was taken for a test drive and low and behold the turbo surging was non existant...however, aside from this guy getting 2 engine codes, he noticed his turbo wouldnt spool up to over 22psi at full throttle...also his vgt solenoid used to be at 85% on the dot at idle, where as now it was closwr to 80-81% and MGP was at .6 when it used to be 0 psi...the guy said his truck idled a little rougher but not terrible by any means...he said he cleared the codes and will wait to see if the PO299 underboost comes back....

so no turbo surging but now only 21-22psi....I cant win! I will ask that guy to ask his friend when he drives it later tonite...thoughts?

Thanks