I have a 2007 DTS. It started making a loud hissing sound upon start up. The service engine light is not on, and the car is not running bad. I plugged in my code reader just to see if anything came up and I got the following code: P2440 Secondary Air Injection System Switching Valve Stuck Open Bank1

Is the valve #11 in the attached graphic? I think the valve is located on the back of the engine closest to the fire wall.

Would taking this valve apart and cleaning it likely solve the problem? Could it also be the solenoid valve or a sensor?

Does the car have less than 50,000 miles on it?
If so, it is under warranty and I think I would let the dealer fix it.

That piece should also be covered under the 8 year/ 80,000 mile emissions warranty.

Jim

If your car is stil covered under the warranty, take it to the dealer, get your loaner car and have them mess with it. I wouldn't mess with something like that and take the chance of invalidating the warranty.

I agree with Superjim and cooncat. Take it to the dealer. The emission warranty is longer than the car warranty (I thought emission warranties went to 100K miles), but what ever it is, your car is still probably covered.

The car has 124,000 miles on it. If it was covered I'd definitely let them take care of it. Ironically I also have a 2001 DTS and I just had to replace the air pump on it last Friday due to water damage, so I'm a little familiar with the secondary air system. But I haven't really been able to find anything on this P2440 code other than the definition.

In that case...124,000 miles...I think your initial thought of #11 in the digram is correct.

When you get to it...be sure to check for loose or broken wires, before spending money on parts.

Texas Jim

A 2007 with 124,000 miles! Somebody has been driving a lot.

Wow how come so many miles? This is not a livery car is it?

We have a family business that is unfortunately about 50 miles from home. Then once we get there the car spends the rest of the day running errands. We rack up miles a lot faster than I'd like to, but I also want to have a comfortable ride while I'm doing it.