CEL - P1411 Secondary Air Injection System
 

I got a CEL this morning and my OBD is telling me it's a P1411 - the Bentley Manual gives two possible causes...

- Signal implausible/ implausible operating range / malfunction
- Short to Ground / below lower limit / lean mixture threshold


Can someone shed a little more light on this?

One thing to note, and I'm not sure if it means anything but this morning it was raining, the first time in several weeks. Also I just recently replace my MAF, not sure if that's related.

The Motronic 7.2 DME Diagnostics manual lists a number of possible causes for P1411 - Secondary air injection system, bank 2.

• A bad secondary air injection pump
  
  restricted air supply lines
  
  electronic changeover valve not functioning
  
  air changeover valve not functioning
  
  vacuum leaks
  
  wiring harness
  
  relay
  
  DME control module

It also calls for a testing procedure using the PIWIS or PST2 tester and calls for specific air temperature and air mass values.

I suspect that since it's isolated to Bank 2, it's probably vacuum leaks or the MAF, at least that's where I'd start. The other causes call for replacement of components and need the tester to isolate them.

So that raises a question. I just had the MAF replaced in July. Later on when looking at the receipt they had my car listed as an S model which it is not. Is the MAF sensor different on an S than it is on the base Boxster? Could it be they installed the wrong MAF?