New LS1 Owners - Newbie Tech - EGR/AIR Block Off plates, what do they do?

im curious as to what these block of plates too, im thinking about getting them, just wanna make sure its okay. I dont have emissions or anything either. will i see any better performance out of the motor?

Block 'em off and don't look back! All the egr stuff is good for is robbing horsepower!

Block 'em off and don't look back! All the egr stuff is good for is robbing horsepower!

Actually the AIR/ EGR don't rob HP at all. The 2 major reasons why people remove them on stock cars are 1. to remove some weight off of the car and 2. it really does clean up the engine bay alot.

To answer the OP's question, the block off plates block off the EGR port on the intake manifold and the AIR ports on the exhaust manifolds so that the manifolds don't leak after the AIR/ EGR systems have been removed on a stock car. Most people who go with headers and an aftermarket manifold don't need block off plates because a lot of aftermarket manifolds can be ordered without the ports for EGR/ AIR.

Actually the AIR/ EGR don't rob HP at all.

I would tend to disagree with that statement. The egr returns unburned fuel vapors back into the intake. Because of this, it also returns some of the exhaust gases as well. By blocking the egr, you are not allowing the unburned mixture to return, and relying more on the fresh air from the front of the intake. Cleaner air= better combustion= better performance= hp.

I do agree that removing it does remove weight, and helps clean up the engine compartment though. Also, taking the egr might lead to worse mileage... But mpg isn't the biggest concern for quit a few of us. Lol

Anyone have pics of this block off plate? Is it the hole on top of the intake that you guys are talking about?

Anyone have pics of this block off plate? Is it the hole on top of the intake that you guys are talking about?

Yes, heres a picture of the hole plugged with an expandable rubber plug sold at advance and auto zone

http://i1124.photobucket.com/albums/l563/mattyfresh89/20120820_235656.jpg

I forget the exact size,i think it was 1&3/8"

Thanks mattyfreshsodef... lol! Didn't know about being able to plug this guy off on my LS1 intake and bought another intake local on CL. Not complaining though... found an LS6 intake w/ rails and injectors for $75... no hole. Score!

Doesn't the AIR Ports also help the catalytic converter that I don't have preform better ;-)

Thanks mattyfreshsodef... lol! Didn't know about being able to plug this guy off on my LS1 intake and bought another intake local on CL. Not complaining though... found an LS6 intake w/ rails and injectors for $75... no hole. Score!

haha no prob man, sweet score on the intake!

Doesn't the AIR Ports also help the catalytic converter that I don't have preform better ;-) ya junk that crap..

The AIR system puts fresh air into the cats to help them hit light off temp faster lowering cold start up emissions. Without cats, it's useless.

And no, the EGR system does not rob any horsepower to a noticable degree. The only issue is the tube sticking down in the air stream. Other than that, it will not rob any power by changing the mixture in the combustion process. Period.

And no, the EGR system does not rob any horsepower to a noticable degree. The only issue is the tube sticking down in the air stream. Other than that, it will not rob any power by changing the mixture in the combustion process. Period.

So putting old exhaust air back into your motor does not harm performance, is that why slp pumps fresh air from the outside atmosphere into every test dyno they run. And yes no reason to have AIR or cats or EGR of you want the most from your engine, in my opinion.

You have to understand how EGR works before you can argue this point.

So putting old exhaust air back into your motor does not harm performance, is that why slp pumps fresh air from the outside atmosphere into every test dyno they run. And yes no reason to have AIR or cats or EGR of you want the most from your engine, in my opinion.

I don't really understand what you are saying by pumping fresh air into the test dyno. If you are talking about opening the hood and having a fan on...this is to keep the car cool since you are not moving (no air flow through the radiator)

Common sense will tell you clean air is better than dirty, however, it just doesn't translate into real hp gains in this case.

Wow haha.. so im guessing this means do the block off plates... TSP sells the set for 14.99, im assuming that comes with the 2 AIR block offs, and the 2 EGR block offs?

Unless you are switching to an ls6 intake or headers without EGR hookups, there is no real reason other than a cleaner looking engine bay to delete them.

Wow haha.. so im guessing this means do the block off plates... TSP sells the set for 14.99, im assuming that comes with the 2 AIR block offs, and the 2 EGR block offs?

If you want to save the $15, you can cut the flanges off of the existing EGR tubes and use some aluminum foil as a gasket to cover the open hole. Just make it fairly thick. I actually used a penny with the foil.

Common sense will tell you clean air is better than dirty, however, it just doesn't translate into real hp gains in this case.

Interesting. I guess the way I pictured it in my mind didn't translate to real world. I am always open to those with more knowledge on a particular subject, and to be honest...EGR ranks low on the list of things I have studied up on.

Thanks for the correction.

EGR is only active during part throttle, low rpm, low engine load cruising conditions. Unless your worried about every horsepower driving down the interstate in 6th gear at 70 mph, it's a moot point.

I am getting a p1404 code which I am told is the egr. Will my car pass a New York state inspection (has cats) w/o the egr. If so, is there a diagram for dummies so I can block it off or remove it? Thanks.

From what I understand, having several friends in ny, any problem that sets off the check engine light will fail you in the state of new York.

Im not schocked, NY sucks w/ emmitions. I have heard about people cleaning it &lor the pinicle but im not sure how to do it or if it is worth a try. Thabks for the reply.

Im not schocked, NY sucks w/ emmitions. I have heard about people cleaning it &lor the pinicle but im not sure how to do it or if it is worth a try. Thabks for the reply.

You can just unbolt it from the flange, 2 bolts & try cleaning the carbon from it with some carb cleaner or combustion chamber cleaner, seafoam they do get jammed by carbon but if it has a P1404 its most likely the sensor thats internal to the egr valve thats faulty.

It does have the 1404 s*&^. Where is it located please? Stupid question, I also got a p0343 cam position sensor they are two totally seperate systems I thought. Wierd that they both went off right after a tune. Except for a lil rough idle the car runs great to me.

ok i know this is a few weeks old but im in the process of getting headers and wanted to go with tsp headers on my 99 z28. but ill have to remove the egr. now there is a hose that goes from manafold to manafold around the back of the motor and i believe it actually has a T in the hose back to the back of the intake is this correct? and if it is do i just block it? do they sell something that blocks it? any help would be great

ok i know this is a few weeks old but im in the process of getting headers and wanted to go with tsp headers on my 99 z28. but ill have to remove the egr. now there is a hose that goes from manafold to manafold around the back of the motor and i believe it actually has a T in the hose back to the back of the intake is this correct? and if it is do i just block it? do they sell something that blocks it? any help would be great

i got a 99 z28 as well and the egr hose that runs around the back of the intake doesnt have a t as far as i can tell, the hose just connects one side to the other. i still have all my egr hooked up, just too afraid to take it off lol.

Oh ok thanks im about to go out and check it out little better

ok i know this is a few weeks old but im in the process of getting headers and wanted to go with tsp headers on my 99 z28. but ill have to remove the egr. now there is a hose that goes from manafold to manafold around the back of the motor and i believe it actually has a T in the hose back to the back of the intake is this correct? and if it is do i just block it? do they sell something that blocks it? any help would be great

That's probably the air system. Does each line have a weird black diaphragm in the middle?

If you're getting headers without emissions junk, there's nothing to block off - you can just pull the air plumbing out and toss it in the trash. Pull the relay for the air pump, and you can yank the pump out if you want - should be behind the turn signal lamps on the driver's side. For the EGR system, you will need one of the expanding rubber plugs to seal the hole in the top of the intake behind the throttle body, unless you already have an LS6 intake.

well looked at it better yesterday, dont know what i was thinking about going to the back of the intake. looks easy to removal all though should clean up nice. thanks for all the help also.