I unpluged my EGR about 1,000 miles ago. I plugged in my scanner and there wee no DTCs. Anyone else have this happen?


I have a 2005 LLY and using the Actron CP9135.Edited by: Smoky

None? Wierd. How many starts in that 1000 miles?


I haven't read my codes yet.

I have started it at least 15 times. I tested the code reader on another car and it found a dtc and cleared it.

No codes on mine according to the Quad tuner /dtc reader . Yaaaa !http://www.dieselplace.com/forum/smileys/Big Smile.gif

Unplugged mine about a week ago and did not notice any significant difference in tubo lag. I have a 200 mile trip that I do on a regular basis and have firm (hand calculated) fuel milage figures that never vary more than .1 or so. I did the trip with the EGR unplugged and there was zero improvement in the MPG. Today I went to AutoZone to find out if there were any codes, but there were none recorded.

Based on the above, the system is acting like the EGR valve was open (system enabled), even though the plug was pulled.

Some of the possibilities that I can think of are:

- I pulled the wrong plug, but I doubt this is the case. The pictures of the plug location seemed to make sense and the truck runs great.

- The EGR valve is defective and is stuck open, but this seems unlikely.

- The valve was open (system enabled) at the time when I pulled the plug, and thus remained open. This is what I am thinking is most likely.

I pulled the plug when the engine was still fairly hot. I know the documentation indicates there is a strong spring that will shut the valve, but I am wondering if it works as documented. I am going to let it sit overnight to cool (if that is possible in Phoenix during the summer), then use the Steve Cole method tomorrow morning (cool engine, run for 30 seconds, shut off engine and pull plug). I hope to do my "bench mark" trip later in the week. I will see if there is any milage improvement.

Questions for those that are not getting any recorded codes:

- Did you disconnect the plug using the Steve Cole method (the engine was cold) or was the engine warm.

- Did you notice any significant improvement in fuel milage or tubo lag, even though there are no recorded codes.

Seems to me that if the valve on my truck was closed when the plug was pulled, I should have had a code and seen some sort of performance improvement.

Note: The truck has the Fed emission package. Edited by: BH in AZ

I unplugged mine cole but I am quite confident that the spring is stiff enough to close it regardless.


You can take out the 4 screws holding the stepper motor in place to confirm it is closed.


I've always said that the biggest advantage of disconnecting the egr is to not have all that exhaust being recirculated.


The extra (if any) fuel mileage improvements and turbo lag improvement are just a bonus.

I unplugged mine cold. Turbo lag is reduced. Added an AFE filter and off the line it feels like my 2003 LB7 did. Fuel mileage seems the same at about 17mpg. I didn't expect to see any difference there...Its to the floor everywhere I go. I drive 120 miles every day. '05 GMC Dmax/Alli


Still no codes with my Actron 9135Edited by: Smoky

Well, I unplugged the EGR plug again this morning after the truck had a chance to cool off overnight. I backed the truck out of the garage, then shut it off. I think this should have been enough time for the EGR system to go into disable status. I then pulled the plug.

I drove the truck about 50 miles with about 7 start cycles, mostly with a warm engine. I stopped by an AutoZone this afteroon to check the codes. The machine again said No Codes Detected.

Max Power, I like your suggestion of pulling the motor to inspect the valve, but since I am not the most experienced guy with a wrench (or screw driver), I am not to anxious to do it just before leaving on a trip. This has something to do with the old saying, "If things can go wrong, they will go wrong".

How difficult is it to get access and then remove the motor. Even more important, what is involved in getting it back on! The lower left area looks kind of tight for space and access.

Thanks.

Edited by: BH in AZ

I'm not mac. http://www.dieselplace.com/forum/smileys/Angry.gifhttp://www.dieselplace.com/forum/smileys/Big Smile.gif


It's pretty easy to pull the motor off. Just tricky to not lose the screws. If you do it, take the intake tube off and it will be easy.

Max Power, Sorry about the name misspelling, I guess your photo had me confused. Actually, I realized it after posting the reply, but my correction and your post crossed in the e-mail.

Thanks for the input. Maybe before starting, I will swing by the auto store (Auto Zone of course) and get one of those long shafts with a magnet on it. That way I can retrieve any dropped screws.

I noticed you said it was easy to get the motor off, but passed on saying it was easy to get back on! I have always been good at taking things apart. Getting them back together is another story.......

Thanks again.

Pulled my EGR plug 1000 Miles ago and no SES light or codes with my Diablo. Mileage didn't change but turbo spool tine decreased.
2004 GMC Sierra 2500HD DURAMAX/ALLISONEdited by: 2k4hd

Pulled my EGR plug 1000 Miles ago and no SES light or codes with my Diablo. Mileage didn't change but turbo spool tine decreased.
2004 GMC Sierra 2500HD LLY DURAMAX/ALLISON

The very first mod I did was disable the EGR by unplugging it. I did this in the morning after the truck sat all night. I have noticed slightly quicker turbo response and there was also a small bump in mileage (efficiency in action!)

Not a single code has been set and it has been disconnected for a month and is driven daily......

How do you it & where is th EGR located? What are the advantages & disadvantages if doing this. I have an 05 GMC duramax/allision

The EGR codes are specific and most scanners will not read them. I have an Actron scanner and I have called them about this. Will also not read low fuel pressure codes. I had 4 codes after unplugging my EGR and my code reader showed none. The dealers did show them.