AusS2000

The reason people lose their minds if you call it an EGR valve is because it's not an EGR valve. Calling it one just perpetuates the ignorance.

It's Secondary Air Injection Valve and is used to allow extra air to be pumped into the exhaust at startup to help heat the catalytic converter to operating temperature.

I realise it's easier to type E, G, and R, but that don't make it right.

Spoolin

Ive always wondered...How do these holes work when they are open? Is it just to tie the exhaust ports together a bit to help with scavenging or what?

AusS2000

Those holes and that channel lead to a port at the back of the head that goes across the head an into the '5th port' on the intake manifold. The 4th port is connected via the valve and plumbing to the pump in the fender at the front of the car.

On start up the pump operates and the valve opens. Air is forced into each exhaust port and out the exhaust through the cat. The extra oxygen added to the rich startup combustion fumes continues the burning and heats the catalytic converter to operating temperature.

After a very short period the pump shuts down and the valve closes and this system goes completely dormant until next cold start up.

Spoolin

^^Does just pulling the secondary air valve off the intake and capping the intake work well enough or is best to also cap the holes like he did in the pic? Is any exhaust coming from the exhaust ports and going into those holes and through the plate and over to the intake side of the head if these holes arent capped like in the pic? My plate that covers those holes has gotten very hot and has bluing on it pretty bad. Is this because those holes are open and the exhaust is trying to travel to the intake side of the head and getting trapped?

I'm just trying to figure out if its even worth capping these little holes like in the pic or just leave it the way I have it with the secondary valve pulled and intake capped. Is there anything negative to leaving these holes open?

AusS2000

The channels and port are open to exhaust gases so no surprise they get hot.

I'd say tapping a putting grub screws is the way to go if you have the head off but otherwise it's a whole lot of work for no gain.

AusS2000

Here 'tis:
"These systems also sometimes include an upstream air injector to admit oxygen to the exhaust system before it reaches the catalytic converter. This precleans the extra-rich exhaust from a cold engine, and helps bring the catalytic converter quickly up to operating temperature."

From:
http://en.wikipedia.org/wiki/Catalytic_converter

Shftat9k

Where is everyone getting the block off plate from?

s2kadrenalin

^ Site Sponsor, S2KPuddyMod & InlinePro (used to, possibly still do??? for $30) sell them.






I blocked mine off too as the Idler Control Valve / Secondary Air Injection Valve leaked boost above 4 psi.

Fixed the problem with the block off plate and found an extra 50whp.

AusS2000

You realise these are two completely separate systems and the Secondary Air Valve isn't exposed to boost?

s2kadrenalin

I still get them mixed up