I want to remove the emissions air tubes from the exhaust manifold but I'm not sure what size plugs to get to seal up the manifold. Can anybody help me with this?

What year /engine ?

They were on ebay.
http://cgi.ebay.com/ebaymotors/Corvet ... ories?hash=item35a5273fd8

I wasn't able to find anything that fit the threads. I was able to build my own by cutting off the tube, and tapping the internal side of the orginal fitting for a 3/8 pipe plug.

Others have cut out the bung and welded in a flat piece of metal, then ground it smooth.

Good luck!

Is this for your 96 lt4?

Off an ebay auction:

Either m18 or m22.

These are AIR block-off plugs for your '96-'97 LT1/LT4 Camaro/Firebird, LT1/LT4 Corvette or LT1 Caprice. The set consists of two block-off plugs to remove the AIR system from your car. These plugs are machined from billet steel. You won't find a nicer plug.

Note: These are M18 x 1.5 plugs that fit *MOST* '96 - '97 LT1 cars. However, it's possible that some '96-'97 cars will require the larger (M22 x 1.5) plugs. Although most '93-'95 cars require the larger (M22 x 1.5) plugs, some "oddball" 1993 and 1995 cars may require these smaller plugs. These plugs will *NOT* work on cars that require the larger (M22 x 1.5) plugs. Please measure the holes in your manifolds/headers before purchasing these plugs. In order for these plugs to work, the inside diameter of your header/exhaust manifold holes must measure roughly 11/16".

Sorry everybody. The car is a 1996 Vette with an LT4.
Thank you for the info, I'm going start this project soon.

what all do you plan to do and why do you want to plug off the manifolds?

I don't want to see you go down a road and not get any results.

I just want to clean up the engine bay. I'm sure it wont give the car any extra horse power.

Do you have any form of visual inspection? That would be my biggest concern.

If your state decides to do it, or you move to s state that does, yuo would be boned.

That's my only concern...

FYI: AIR is only used at start up for cold start emissions... For the most part the fan is done within a mile.

On LT1s, the AIR plumbing is used for EGR, too, but the LT4 doesn't have EGR. Cam overlap took care of that.

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Thats what I did.

I wonder why air was required on the Y bodies....when it was legally removed from the b-bodies?


Technical - Water in AIR Pump and/or DTC P0410, P0412, P0415, P0416, P0100, P0101, P0102 or DTC 48 (AIR System Disable Procedure) #01-06-04-011

Water in AIR Pump and/or DTC P0410, P0412, P0415, P0416, P0100, P0101, P0102 or DTC 48 (AIR System Disable Procedure)
1995-1996 Buick Roadmaster
1995-1996 Cadillac Fleetwood
1995-1996 Chevrolet Caprice, Impala SS
with 4.3L or 5.7L Engine (VINs W, P -- RPOs L99, LT1)
Condition
Some customers may comment of a hesitation during heavy/full throttle acceleration.
A 1996 vehicle may also set any of the following DTCs:
P0410
P0412
P1415
P1416
P0100
P0101
P0102
A 1995 vehicle may set a DTC 48.
There will also be evidence of water in the AIR pump.
Cause

Under high engine speed and load conditions, hot exhaust gasses may leak past the air check valves. As the exhaust gasses in the air tube cool, water vapors collect into the AIR pump. As the vehicle is driven, condensation from the AIR pump may come into contact with the Mass Airflow Sensor through the AIR inlet hose. This condition may cause a hesitation on acceleration and may also set the DTCs.
Correction

To correct this condition, a Secondary AIR Injection Pump disable procedure has been developed. (It has been determined that the Secondary AIR Injection system is not required to meet emission requirements for these vehicles only.) In other words, you can remove the AIR System all together and on a 96 model B-Bodys, A GM Dealer will reprogram your PCM to delete the AIR System out of it per the TSB (Technical service bulletin) #01-06-04-011. Just give them that number if you still have the AIR system in your car and want to get rid of it. There also a Sticker they put on the Radiator support of the car for those that have to do Emissions testing that says it's been legally removed.
__________________

Do you honestly expect smog laws to make sense? Tear the crap off and throw it in a box in case you need it in the future.

My vette passed the California "advanced" smog test with a single high flow cat, and no air pump or diverter valve crap.

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I just find it odd that my 95 LT1 equiped Impala SS has all of the AIR equipment removed and a sticker stating the dealer did it legally.....while the LT1 in my corvette has to remain saddled by equipment that obviously is unnecessary.



Mike

Agreed.

I find it odd that in 1985, it's legal to have a Corvette with no pre-cats. In 1986, with the exact same motor, it's not.

I also find it odd there's no smog-legal long tube headers for 84-85 vettes, since it would be perfectly legal to make one. There are long tubes that would pass the test, but nobody ever paid the state for the approval sticker.

The 85-87 TPI Camaro has smog legal long tubes and has the same motor and emissions controls. They were tested and shown not to increase emissions on the Camaro. But it's against the law to install those on my vette.

But you are talking Kali......feds allowed removal of air on Impalas...


MikeQuote: