Not to mention that on the newer vehicles, blocking off the EGR would cause an SES light.

The function of the EGR valve is to reduce NOx emissions by lowering cylinder temperatures without really hindering performance. The only real downside is a much dirtier intake... Anyone that says they got better performance with their EGR valve blocked off is smoking something.

 

On the newer trucks you don't have to completely block off the EGR. It can be restricted but you do have to make sure that the restriction allows enough gas to pass so as not to set off the MIL/SES light in the dash.

You can search the internet and there are people selling these restrictors for $40 approx.. The restrictor fits inbetween the EGR supply tube and the intake manifold behind the A/C compressor. But there are other ways to do it. One of my ideas is to make/take a flat washer with the diameter hole needed to properly restrict the EGR and place it into the area of the intake that the EGR supply tube screws into...But the method I used was to drill out the lower section for the EGR supply with a 9/16 drill and tap for a 3/8NPT thread and then find a block plug in the junkyard from another intake or block and drill it with a 5/24 hole and then use a socket head wrench to seat it so that it is flush with the ledge of the supply connection and there it is less than $20 dollars...

 

I only recommended blocking it off if your like me and cant afford to fix the same problem these trucks are known for over and over again at approx. $200 a time. I wouldn't block it off if your driving a new vehicle but I have a 94 blazer 4.3 vortec HO and I blocked it off about 6 months ago and haven't had a problem with it since. You would only run into problems if you drive it off road in the thick mud where the engine is running really hot but if your mostly on pavement driving normally iv been told by a mechanic it wont hurt your truck. And I never said the truck ran better with it blocked off rather than replacing it but it runs 100% better then with it stuck open.

 

would restricting it improve a 92 w/165,000's mileage or performance. otherwise a new egr is around 50-75 bucks, and if its faulty id probably just buy it rather then drilling out and tapping the block, plus what inner and outer diameters would u need with the washer. too much work for me, two bolts on an egr is alot simpler then hunting down old blocks in a junkyard. but thats just me.