Powertrain, generic (extended)

P2443 AIR System Switching Valve Stuck Closed (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P2443 signals that the bank 2 secondary air valve stays shut although the engine computer commands it open, so the second bank gets no added air during warm-up. Subaru lists the code for the 2011–2015 WRX STI and recommends always following the diagnosis for the opposite bank too, since valve or hose faults on one side can show up on the other. Toyota's 2UZ-FE bulletin covers only the bank 1 equivalent. Under CARB rules, each bank's air supply must be judged on its own wherever a blocked bank would raise emissions measurably. Common causes are a seized valve, a leaking vacuum supply or control solenoid, and kinked hoses. Expect slightly higher cold-start emissions and a failed readiness check; driving is normal. P2441 is the bank 1 code.

Likely causes

Bank 2 valve seized in the closed position
Leaking vacuum line or faulty control solenoid
Kinked air hose on the bank 2 side

Symptoms

  • Check engine lamp after a cold start
  • Secondary air readiness not set

Repair estimate

DifficultyMediumDIY possible
Parts and labour€120–800
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

secondary air switching valvesecondary air vacuum lines

Related codes

P2441P2442P0492

References: static.nhtsa.gov, law.cornell.edu.