P2442: a bank 2 air-valve stuck-open judgment can use lambda correction

P2442 identifies a bank 2 secondary-air valve stuck open. In Audi's CTUA diagnostic chart, the listed criterion is lambda-controller deviation greater than 15 percent. The controller's judgment is therefore supported by a mixture-control response, rather than a direct mechanical measurement of the valve's position in this row.

A stuck-open label still needs physical confirmation

As diagnostic interpretation, a lambda-control deviation must be explained within the correct secondary-air test conditions before it can justify a valve replacement. The table supplies a detection relationship, not proof that an inspected valve is mechanically jammed.

The percentage also should not be rewritten as valve opening, air pressure or oxygen concentration. It belongs to the lambda-controller deviation named by the source. Confusing those quantities would create a test that the book does not provide.

Apply the CTUA criterion to the CTUA system

Audi describes other air-valve monitoring methods elsewhere in the reference, so the engine section matters. Identify the actual bank 2 valve and applicable procedure before using a threshold. The quick-reference row contains no pinout or component-removal instructions. A useful diagnosis links the monitored control response to a demonstrated defect rather than treating P2442 as a universal command to replace the secondary-air assembly.

Source: Audi 2014 A6/S6 Quick Reference Specification Book.