987 · Exhaust

P1411

Secondary Air Injection System, Bank 2 - Insufficient Flow

LOW SEVERITY

Porsche-specific secondary-air code for bank 2 (cylinders 4-6). Where generic OBD-II uses P0413/P0411 for bank 2, the Porsche DME logs P1411, and it very commonly appears paired with the generic P0410 (bank 1). The secondary-air system pumps fresh air into the exhaust ports for ~90 seconds after a cold start to light off the catalysts; this code sets when measured air flow is implausible. Only monitored during the cold-start SAI cycle.

SYMPTOMS

  • Check-engine light (often after a cold start)
  • Brief rough idle / raised idle when cold
  • Buzzing air-pump noise on cold start
  • Usually no warm-running symptoms

LIKELY CAUSES

  • Brittle, cracked secondary-air plastic hoses (over 80% of these codes)
  • Stuck or seized combi/change-over valve
  • Failed secondary-air injection pump
  • Vacuum leak or failed check valve in the SAI control circuit
  • Carbon-clogged air passages into the heads

DIAGNOSIS STEPS

  • Confirm the code sets only during the cold-start SAI window
  • Inspect the SAI hoses for cracks/brittleness and the change-over valve for sticking
  • Verify the SAI pump runs on cold start (listen/measure current)
  • Check control vacuum and the check valve
  • Clear codes and re-test on a cold start

RELATED PARTS

  • Secondary air injection hoses
  • Air change-over / combi valve
  • Secondary air injection pump
← All 987 codes987 hubFault finding
FLAT

Rank symptoms to causes in your garage.

Sign in for the full fault finder — ranked causes and known issues for your exact car.

Start your garage