Offroad-Express

Thought I'd share this here as it's such a common topic and I know I struggled to get definate answers..
Problem is with this sort of thing is you get people giving you an answer based on what they have heard or read not based on personal experience..

So if you are contimplating doing the egr removal on the 3.1 efi diesel which is post 1995.
It is as simple as removing all the egr piping and valves off the intake and plugging the 2 vacuum hoses... Done.

I was told I had to run a new vacuum feed to the front diff for the 4wd activate, these have an add system where vacuum is required to move a collar to engage the axles to the diff... I was told the two vacuum hoses that you remove from the egr are part of the 4wd system but it looks like they are not.. or atleast not directly linked..

I've just plugged the 2 hoses and the 4wd still works instantly.

I understand vacuum is gained from the pump on the back of the alternator, there's also a reservoir on the passenger side which I'm only assuming is used to hold air, a holding tank as such...

The only other thing that these vacuum hoses were supposedly responsible for is to activate idle up for when ac is on and your idling, it increases revs by only 100-200rpm.. most don't bother if this works or not as it's a very minor function that most don't notice anyway..

Chur

if you plug the hoses on the actuator side of the solenoid then no other system will be effected regardless of vehicle.
the only trap with 90's egr system is if they run an intake butterfly that restricts air flow as part of the egr system. you need to disable that if you have it.

My understanding is that butterfly is not present in the efi models.
There's a port in the intercooler that feeds a vacuum signal to the mechanical pump on non efi models, in the housing where that butterfly is, in the efi models that port is plugged from factory