it doesnt...

 

Thats what I thought...

 

i believe that the egr block off does ad hp. but its only a little. meaning maybe only 1-2. there is no way that you can feel 1-2 hp rite away. you need at least 10 to notice.
what the egr block off does is blocks off the hot air from the exhaust. thats about it. breathing cooler air. but breating cooler air eats more gas. more gas to you engine is more power. but timing advancment and air fuel ratios must be all even.

 

EGR is just a method of controlling NOx emissions, that's all it is for. It is only supposed to operate under cruising conditions, at idle or under WOT it's not supposed to activate, so basically if I had a track car I'd just get rid of it with all emission devices, but if it's a daily driver, you're going to see no difference except higher NOx readings on a smog test.

 

So the valve doesn't close after the engine is warm? If you block it wouldn't that throw a code?

 

it wont throw a code, your oxygen sensor would read more oxygen in the exhast then it would make the car run richer then making your car less fuel efficient.

 

Actually there are codes for the EGR system that monitor it's efficiency, but I honestly don't remember if they were on OBD1 systems. The EGR is supposed to be a normally-closed valve. Warm-up, idle, WOT, during all of this it should remained closed. It's only supposed to open while you are cruising. So blocking it off is pointless, it wouldn't cause any increase in performance unless your EGR is effed-up and is sticking open when it shouldn't be.

 

Yeah it ,may throw a code, but it will be for the o2 sensor, because the computer doesnt know if the egr valve is opening or not it only runs off of vacuum, it will just read that there is too much oxygen then make the car run rich, but if it does throw a code it would most likely be a code for the o2 sensor.

 

So the EGR valve does close under WOT? Is there a valve for the TB coolant lines? Does blocking that help at all?