Mp8 problems after deleted

[Leonardob]

Mack mp8 2012 gu713 granite.

I have a 2012 mack granite that had flaws at the time of doing the regeneration, we decided to clean certain things and change the turbo for an original mack one and it continued to give problems of def.

We decided to eliminate the DEF and the truck was left with RPM failures, attached link to the video

https://vimeo.com/987828534?share=copy

This fault lasts a few seconds and then it is removed and the truck remains calm. If I touch the accelerator or the clutch, the fault occurs again.

We thought it was problems with injectors and they were changed with their cup. And even the fault still exists.

I don’t have any associated codes, I’m attaching a photo.

The programmer tells me that that failure has nothing to do with the elimination.

In addition to this, when the road test I feel the truck without strength until it reaches 1600rpm that I feel that the turbo has its effect and the truck grabs some speed 

I really don’t know what to do anymore, I’ve invested a lot of money and I still can’t work

[BOBWhite]

Time for a different tuner! If they can't get it to run right then it's something in the programing I would say. But I don't know much of anything about deleting/tuning 

Deleting a truck makes it much harder to sell too. Good luck!

[Mackpro]

Some of the delete programs also do the EGR valve and some don’t. I would unplug the EGR valve and run it. The deletes on Mack’s are so hard to get right because of so many changes between every 2 years of production.  2008-2009 were DPF only. 2010-2012  DPF and DEF/SCR non-OBD. 2013-2014 was a big jump in wiring and in software to OBD. 2015-2016 was the GHG greenhouse gas emissions years with different software and injectors. Then common rail started in 2017. Biggest complaint after a delete is the fan clutch either won’t come on and the truck over heats or it’s stuck on all the time. Followed closely by the truck has no power now after the delete. Usually caused by EGR deleted and not unplugged and blocked off. Even if EGR is deleted and blocked it the valve still  need to be unplugged. Also on some years the turbo actuator was on the same data link as the DEF level sensor. Wrong delete gets put in to kill the DEF level sensor and it also kills the turbo actuator. 

[Leonardob]

6 minutes ago, Mackpro said:

Some of the delete programs also do the EGR valve and some don’t. I would unplug the EGR valve and run it. The deletes on Mack’s are so hard to get right because of so many changes between every 2 years of production.  2008-2009 were DPF only. 2010-2012  DPF and DEF/SCR non-OBD. 2013-2014 was a big jump in wiring and in software to OBD. 2015-2016 was the GHG greenhouse gas emissions years with different software and injectors. Then common rail started in 2017. Biggest complaint after a delete is the fan clutch either won’t come on and the truck over heats or it’s stuck on all the time. Followed closely by the truck has no power now after the delete. Usually caused by EGR deleted and not unplugged and blocked off. Even if EGR is deleted and blocked it the valve still  need to be unplugged. Also on some years the turbo actuator was on the same data link as the DEF level sensor. Wrong delete gets put in to kill the DEF level sensor and it also kills the turbo actuator. 

Will you have any photos of the sensor that I should disconnect?

[Mackpro]

The EGR valve is on the RH side of the engine bolted to  the exhaust manifold towards the rear . The EGR valve has about a 6 “ harness coming off of it with a 2 wire connector. This connector is usually zip tied to the very center of the back of the engine. You have to remove the lower center of the dash and remove the firewall engine cover to get to it. 

[Leonardob]

21 hours ago, Mackpro said:

The EGR valve is on the RH side of the engine bolted to  the exhaust manifold towards the rear . The EGR valve has about a 6 “ harness coming off of it with a 2 wire connector. This connector is usually zip tied to the very center of the back of the engine. You have to remove the lower center of the dash and remove the firewall engine cover to get to it. 

You are the best… problem solved. Thanks 

[Mackpro]

Good deal!!! 

[mp8_macky]

Make sure to use trusted vendor for Macks.
I've been using these guys for last 10 years, and I had no problems https://truckecmtunes.com/mack-dpf-egr-def-scr-delete.html

[Arty]

Hello I’m new to this forum. I just recently had my 2013 non obd Mack with mp8 505 fully deleted by a guy near me. The first tune was ok except the Jake/exhaust brake was weak and the truck was jumpy when coasting. So it was switched to a drunklab tune and it’s more drivable and the Jake is good but I’m not happy with it. I’m concerned because it makes a bunch of boost, whistles like a jet, the oil temp is higher than stock and I have quite a bit less power. Any ideas?

[Mackpro]

Every deleted MP8 I have ever seen never ran better after the delete except for 3 and after about a couple of months all 3 cracked intake/exhaust valves and took out the turbo and head. The only good safe tune I have seen is the Mexican export D13 which has 465 HP and has EGR but no DPF/DEF. This file works great in both Mack and Volvo but is only set up for Horton air fan as the export Volvo only uses the air fan. In the US, Volvo seems to use the air fan clutch in about 70% of there trucks while Mack is probably more like 10%. So using this file in a Mack with an electric viscus fan requires some extra wiring. Also , sometimes with the Mack the dash cluster will have a fault code for DEF gauge not working unless the correct pre-DEF software is flashed over dash cluster. This must be hard to do as most Mack’s I’ve seen almost always have this fault code .  

[Arty]

I had a lot of concerns about deleting it. I asked many questions before proceeding and he said they have not had any issues at all. The only reason I did it was because it was doing the regen often and it’s a farm truck so I didn’t want to burn down fields.

now I’m not sure if I should reverse it back

[Arty]

I guess the alternative is where can I get this export tune?

[fjh]

On 5/8/2025 at 7:38 AM, Mackpro said:

Every deleted MP8 I have ever seen never ran better after the delete except for 3 and after about a couple of months all 3 cracked intake/exhaust valves and took out the turbo and head. The only good safe tune I have seen is the Mexican export D13 which has 465 HP and has EGR but no DPF/DEF. This file works great in both Mack and Volvo but is only set up for Horton air fan as the export Volvo only uses the air fan. In the US, Volvo seems to use the air fan clutch in about 70% of there trucks while Mack is probably more like 10%. So using this file in a Mack with an electric viscus fan requires some extra wiring. Also , sometimes with the Mack the dash cluster will have a fault code for DEF gauge not working unless the correct pre-DEF software is flashed over dash cluster. This must be hard to do as most Mack’s I’ve seen almost always have this fault code .  

yup deletes  are  very dicey situation  !  Removing the exhaust from the air mix creates more  heat in my mind this in turn puts more stress on valves that weren't intended to have that heat in the cylinder ! something in the programming has to change to lessen that impact either a a timing reset or less fuel/air! Can't name how many ISX heads I seen and heard of turned into shower heads over deletes gone side ways!