AIR system

[NRWhiteKnight]

I have been considering putting headers on my 98 Yukon. I see listing for vehicles with and without the AIR system. Are vehicles from Cali (or other highly emissions regulated states) the ones that have this system or is it for vehicles in all 50 states? I did a search but turned up so many results that were not related, I felt it easier to ask.

Thanks in advance for any and all info.

 

[99thomas]

Look at your exhaust manifold on the driver side, if there is a braided pipe going from the intake to the back of the exhaust manifold you have AIR, if not then you dont, i have it on my tahoe and im in mn.

 

[NRWhiteKnight]

I have it on mine then. I remember seeing the braided pipe.

Thanks.

 

[99thomas]

If your putting headers on, be carefull removing the pipe, mine twisted right off, had to order a new one, dont remember for sure but i dont think it was just a cheep piece.

 

[NRWhiteKnight]

I'm thinking the Pace Setter shorty headers. Then maybe later on do the rest of the exhaust or go with the Flowmaster 50 muffler. Not sure yet, tho.

 

[SunlitComet]

STOP!!!

First the braided line on left rear manifold to intake is your EGR line not AIR.

Second if you have A.I.R. you will have a pump in the forward left corner of the engine and you will have lines going to the exhaust manifolds.

While it is near impossible to find mid/long street legal headers lately there are plentys of shorties around that are fitted for the engines that have the A.I.R. system and ones that dont. JBA makes an excellent set of headers for both and is available in several different coatings.

 

[Fishin757]

quick question.... whats the AIR system do?

 

[SunlitComet]

The electric motor Secondary Air Injection (AIR) system is used on the 5.7L to reduce Carbon Monoxide (CO) and Hydrocarbons (HC) .

The AIR system adds air (oxygen) to the exhaust manifold to continue oxidation after the exhaust gasses have left the combustion chamber. The heat from this reaction brings the catalytic converter up to operating temperature taster when the engine is cold. This system consists of an electric AIR pump, check valves, and necessary plumbing.


An electric motor AIR pump supplies filtered air from the air intake system to the AIR injection pipes.

The check valves, on the AIR injection pipes, prevent backflow of exhaust gasses in the AIR pump.

When the engine is started with a coolant temperature above approximately 15°C (45°F) or if the fuel system is in the Decel Mode, the VCM energizes the AIR relay. The AIR relay then energizes the AIR clutch, which directs air into the exhaust manifold ports.

The control module may turn the AIR pump OFF when any of the following conditions occur:

The system is in the Closed Loop mode
Any DTCs are set
The system is in Power Enrichment mode for more than a short period of time
Low manifold pressure (over run)
Quick vacuum rise (rapid decel)

 

[NRWhiteKnight]

STOP!!!

First the braided line on left rear manifold to intake is your EGR line not AIR.

Second if you have A.I.R. you will have a pump in the forward left corner of the engine and you will have lines going to the exhaust manifolds.

While it is near impossible to find mid/long street legal headers lately there are plentys of shorties around that are fitted for the engines that have the A.I.R. system and ones that dont. JBA makes an excellent set of headers for both and is available in several different coatings.

Lower left corner looking from the front of the vehicle at the engine, correct?

Are the JBA shorty headers better than the Pace Setters or is it more of a personal preference?

I was thinking of these: http://www.summitracing.com/parts/psm-70-1320/media/images/year/1998/make/gmc/model/yukon

 

[99thomas]

Lol, forgot yeah egr, thus why it took me forever to figure out what the part was to replace, correct name works better, but if your looking at the engine from the front its on the right.