Some of you may remember my dilemma, and if not, and you care to read about it, here is the prior thread:
http://www.svtperformance.com/forums/showthread.php?s=&threadid=30345
and
http://www.svtperformance.com/forums/showthread.php?s=&threadid=14547
Basically, what it boils down to is that my DPFE hose keeps blowing off at part throttle and WOT. My car also has a slight surge to it when cold and cruising under part throttle, and when it fully warms up it does not do this anymore. The car is completely factory stock, and has not been modded in any way.
Now on to today...
Okay, well, got my car back from the dealer today and on the way home the check engine light (SES) came on again. Whip it around and back to the dealer, popped the hood, and the same hose is off again. For those of you who aren't aware of what this hose is, it is the DPFE hose, which stands for Differential Pressure Feedback EGR. This hose goes directly down to the metal EGR tube that comes right off the driver's side manifold. This started popping off after about 200 miles on the car, and each time triggers the SES. The dealer ordered a complete new h-pipe, which included all 4 catalytic converters, and today they replaced it. On my service ticket it states:
So you will know:
P1405 = Differential Pressure Feedback Sensor Upstream Hose Off Or Plugged
P1111 = System Pass
There is a good possibility that my new cats are clogged yet again. I just do not understand this. I have the latest pcm calibration (YDH1) as well. I do know that my car has been running pig rich as well, as I measured the afr via my FJO. I datalogged it to my laptop, and the graph is attached below.
Anyhoo, could it be that the factory pcm calibration is causing the car to run so rich that it is fouling the cats out within 20 miles? I find this quite amazing if so, especially since I stayed mainly around stoich (14.7 afr) after I left the dealer when the SES light came on again (I wasn't measuring, just that I was driving part throttle and cruising, so that is why I'm figuring I was at or close to stoich). Any other ideas or those with similar issues, and if so, what were your resolves?
http://www.svtperformance.com/forums/showthread.php?s=&threadid=30345
and
http://www.svtperformance.com/forums/showthread.php?s=&threadid=14547
Basically, what it boils down to is that my DPFE hose keeps blowing off at part throttle and WOT. My car also has a slight surge to it when cold and cruising under part throttle, and when it fully warms up it does not do this anymore. The car is completely factory stock, and has not been modded in any way.
Now on to today...
Okay, well, got my car back from the dealer today and on the way home the check engine light (SES) came on again. Whip it around and back to the dealer, popped the hood, and the same hose is off again. For those of you who aren't aware of what this hose is, it is the DPFE hose, which stands for Differential Pressure Feedback EGR. This hose goes directly down to the metal EGR tube that comes right off the driver's side manifold. This started popping off after about 200 miles on the car, and each time triggers the SES. The dealer ordered a complete new h-pipe, which included all 4 catalytic converters, and today they replaced it. On my service ticket it states:
CUSTOMER STATES THE CHECK ENGINE LIGHT CAME BACK ON. KEEPS
BLOWING THE DPFE HOSE OFF.
QUICK TEST KOEO P111 KOEC P1405. RUN PINPOINT TEST.
ROAD TEST. CK DPFE HOSE. OK. HOOK UP VAC GUAGE TO CK
MANIFOLD PRESSURE ON DPFE HOSE. CALL HOTLINE. TOLD TO
CK CATALYTIC CONVERTER. REPLACE CAT CONVERTER. RETEST
ROAD TEST 20 MILES. CLEAR CODES. RETEST KOER P1111
W? 606 5F250 42 M-TIME SEE RO
So you will know:
P1405 = Differential Pressure Feedback Sensor Upstream Hose Off Or Plugged
P1111 = System Pass
There is a good possibility that my new cats are clogged yet again. I just do not understand this. I have the latest pcm calibration (YDH1) as well. I do know that my car has been running pig rich as well, as I measured the afr via my FJO. I datalogged it to my laptop, and the graph is attached below.
Anyhoo, could it be that the factory pcm calibration is causing the car to run so rich that it is fouling the cats out within 20 miles? I find this quite amazing if so, especially since I stayed mainly around stoich (14.7 afr) after I left the dealer when the SES light came on again (I wasn't measuring, just that I was driving part throttle and cruising, so that is why I'm figuring I was at or close to stoich). Any other ideas or those with similar issues, and if so, what were your resolves?
Last edited: