What is this?

[SMWS6TA]

This weekend when I was changing plugs & wires, I had to move something that was attached to the exhaust manifolds. As you stand on the drivers side looking at the plugs/wires/exhaust maifold, a tube comes up from the exhaust manifold near the most forward plug, this tube is attached to a hose that goes towards the rear of the engine compartment. It is on both sides. I know pics would be easier to show, but can't at moment.

is this EGR or something else?

[2001NBMZ28]

Sounds like you're describing the secondary air system, does it have a check valve in between the metal pipe and hose?

[pajeff02]

It is the secondary air system. At start up an electric pump, which is located in front of your driver side wheel well, activates. The pump draws air from the tube coming from the driver side of your air baffle (filtered air) and pushes it through the hose running up over the top of your driver side wheel well, in the engine bay.

The tubing connects to a valve which is operated by an electric/vacuum solenoid. This is located on the top of your engine, rear driver side. Two tubes exit the valve - one to each side of the motor. There are check valves located where the tubes transition from a rubber line to steel. These tend to go bad with time and will throw SES codes.

The air then enters each exhaust manifold through the tubes you initially described. The pump only runs for about 2 minutes or so and the additional air brings the cats up to operating temp quicker to help with emissions.

[SMWS6TA]

It is the secondary air system. At start up an electric pump, which is located in front of your driver side wheel well, activates. The pump draws air from the tube coming from the driver side of your air baffle (filtered air) and pushes it through the hose running up over the top of your driver side wheel well, in the engine bay.

The tubing connects to a valve which is operated by an electric/vacuum solenoid. This is located on the top of your engine, rear driver side. Two tubes exit the valve - one to each side of the motor. There are check valves located where the tubes transition from a rubber line to steel. These tend to go bad with time and will throw SES codes.

The air then enters each exhaust manifold through the tubes you initially described. The pump only runs for about 2 minutes or so and the additional air brings the cats up to operating temp quicker to help with emissions.

Ok, I understand. Next question I have is when I get headers, what do I do with these? I live in AL and have no emmissions here, hell no inspections.

[pajeff02]

The secondary air system gets removed and the vacuum line capped off -- shouldn't take long and not difficult to do. Then you will need to have a tuner delete your secondary air on your PCM or it will trigger the SES light. Check with Tune by Frost -- site sponsor -- he can fill you in on the details.

[SMWS6TA]

Thanks, so many damn details...nothing simple anymore.....Glad I asked, I'm planning on headers in the next few months....

[Turrry]

The secondary air system gets removed and the vacuum line capped off -- shouldn't take long and not difficult to do. Then you will need to have a tuner delete your secondary air on your PCM or it will trigger the SES light. Check with Tune by Frost -- site sponsor -- he can fill you in on the details.

Where does the line get capped off, and what do you use to cap it?

[pajeff02]

Where does the line get capped off, and what do you use to cap it?

TSS posted an earlier thread on this -- I am pretty sure this will answer your question: http://www.ls1.com/forums/showthread.php?t=108669