1993 4.3 EGR Delete

[DreamRyder1963]

I am wanting to due an EGR/ Emissions delete on the 4.3 in my '93 Sierra. My goal is to gain a bit of power without tripping the SES light. I know that this in not considered Kosher in many areas but we do not have emissions testing in my area. Plus it is very common place on trucks. Has anyone done this before?

[Zane M]

I haven't done it myself, but I believe it is as simple as making/buying a block off plate, and getting the EGR function tuned out of your memcal.

[DreamRyder1963]

I was thinking it was that simple, but I was wondering if that would cause the SES light to stay on. Better question is, would the engine gain enough power to even bother with it?

[Tx Firefighter]

Yes, it will trigger a check engine light. No, you won't feel any power increase. The EGR valve isn't your enemy.

[DreamRyder1963]

I was starting to wonder about that. The only real exposure I have had to egrs is early 2000s desiel trucks. They tend to pick up a decent amount of power with a EGR delete.

[Tx Firefighter]

I agree, if I had a diesel the first thing I'd do is start deleting. No doubt. The gas engine is a different matter though.

[Zane M]

Originally Posted by DreamRyder1963

I was thinking it was that simple, but I was wondering if that would cause the SES light to stay on. Better question is, would the engine gain enough power to even bother with it?

That is why I mentioned you would need to get the EGR function tuned out of the memcal-to avoid the SES light.

But as has been pointed out, there really isn't much benefit of deleting the EGR function on these engines.

[DreamRyder1963]

My SES light is giving me code 32 which according to the Haynes Manuel I was looking at is a bad EGR or vacuum leak. I fixed a vacuum leak from a hose that broke on the vapor canister. The manuel suggested that to test the EGR, I just need to see if it will move up and down. Is there a better way to check it?

[Tx Firefighter]

Start the engine and let it idle. Now, reach under the EGR valve and open it with your fingers. How does the engine react ? It should begin to run very rough when you open the valve.

Report back.

[DreamRyder1963]

Originally Posted by Tx Firefighter

Start the engine and let it idle. Now, reach under the EGR valve and open it with your fingers. How does the engine react ? It should begin to run very rough when you open the valve.

Report back.

Sounds good. I will try it in the morning.