Ingenere

I've had my '03 SL55 since new. It has been very reliable and a great car. However, I have had the secondary air pump fail for the 2nd time. First time was about 10 years ago.

If you have this problem you will get a CEL, the code is specific and states secondary air injection failure.

It's an easy job. the pump is located ahead of the right front wheel. You'll need 3 things:

The pump
relay
40 Amp fuse

Once you lift the car and remove the wheel and front fender liner, you'll see the pump. 3 bolts hold it in place. You'll remove the air hose and 1 wire harness. It's a bit fiddly, but it comes right out.
You reuse the old bracket. It goes back together in reverse order.

The relay and fuse are located in the fuse box in the engine bay, just to the left of the battery.

The whole job will take a couple of hours, and you'll have to clear the code.

I think the parts were less than $300. An Indy quoted me $1200. I love doing my own work!