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+--- Thread: DPF differential Pressure problems (/showthread.php?tid=642)
DPF differential Pressure problems - trdodd07 - 07-19-2016
After doing an egr tuneup and replacing the aftertreatment injector, I am now faced with dpf diff. pressure codes. Was on a load and got about 165 mi in and the parked regen light came on, then a couple seconds later, it started blinking, followed by the check engine light, then the stop light. I am thinking it is a sensor related issue due to how quick it cycles through to the stop engine light. Aftertreatment history shows in the 2 - 3 range, but when I do a forced regen, the diff pressure is at around .55 roughly once it's complete. I am leaning towards a faulty dpf diff sensor since all 3 (Slight, moderate, severe) are showing up. Trying to get this figured out so I can get this load up to MT by Fri. Anything else to also consider as a possible cause other than the DPF filter? EGT is in the upper 4 to 500's even at low to no boost, and boost is also low (20 - 25 max) at 100%. I was getting an IMAP code, so I swapped it with a new one I had and it hasn't returned as of yet. Thanks for any info!
RE: DPF differential Pressure problems - joed2323 - 07-19-2016
Has the dpf filter/do ever been removed? Inspected or cleaned?
Alot of times just changing that sensor doesn't help. Its definitely worth a shot.
Ive had dpf filters cleaned before and I swear the dealership doesnt do a good job cleaning them.
This one truck had numerous differential pressure codes, we had the dpf and doc cleaned and still the same codes. Finally I.said f it and replaced the filter with a brand new dpf, haven't had problems since.
Im not sure why getting the dpf filter doesn't always work. But starting to think just replacing it with a new filter is the way to go instead of constant nagging diff psi codes.
Maybe someone with more knowledge can explain why getting the filter cleaned by a dealership doesnt always work
RE: DPF differential Pressure problems - Rawze - 07-19-2016
* Sometimes the tubes for the DPF Diff. pressure sensor (DPF Delta-P sensor) down at the DPF will clog up, or the rubber boots where they meet the sensor get cracked.
* sometimes the DPF itself is simply cracked and is restrictive.
* sometimes it is due to someone changing the ECM software in an attempt to "uprate" the power incorrectly.
* Sometimes the computer simply gets confused and will flag it after it has been cleaned, making the alarms more sensitive.
* sometimes it is bad readings from other sensors and/or a stuck EGR valve causing excess soot.
* sometimes it is coolant or oil intrusion.
* Sometimes it is simply the fact that the DOC or DPF is very old and the chemicals in them have been washed out.
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You have my number, I PM it to you a while back. You are welcome to call me sometime. -- Rawze.
RE: DPF differential Pressure problems - trdodd07 - 07-19-2016
(07-19-2016 )Rawze Wrote: * sometimes it is bad readings from other sensors and/or a stuck EGR valve causing excess soot.
You have my number, I PM it to you a while back. You are welcome to call me sometime. -- Rawze.
That was going to be my next step, but I wasn't ready to throw in the towel and call the help line just yet, lol. I gave it some thought, and watched your videos on the tune up again and remembered that every time the dpf diff codes would come back up, so did a code for the IMAP. I remembered that the IMAP doesn't usually throw a code unless it is really messed up, so I swapped it out. Did a forced regen, which put all the dpf alarms inactive, and let it cool off before turning in for my break since by then it was 1am. Once I started my shift today, I could tell that it was running a lot better. My mpg's came back up as well as boost at max load. Hasn't called for a passive regen yet, which was an issue before all the Christmas lights would come on. I could force regen it, and wouldn't even be out of the parking lot before it was trying to do a passive one. Been watching it all day and so far, there have not been any codes. If I get anymore grief from it though, I'll be making that phone call for sure!