P2435

Air Injection System Air Flow/Pressure Sensor Circuit Bank 2

P2435 is a generic OBD-II powertrain diagnostic trouble code: Air Injection System Air Flow/Pressure Sensor Circuit Bank 2. It is logged by the engine control unit when the air/maf monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P2435
Group
Powertrain
System
Air/MAF
Severity
Warning (MIL on)
Need P2435 disabled?
RaceTune permanently disables any OBD-II trouble code on supported ECUs — for motorsport, off-road, and export use.
→

What P2435 means

P2435 indicates the PCM has determined that the secondary air injection (SAI) switching valve for Bank 1 is stuck in the open position. Secondary air injection systems pump fresh air into the exhaust stream immediately after a cold start to accelerate catalyst light-off and reduce hydrocarbon and carbon monoxide emissions during the engine warm-up phase. The switching valve directs air from the pump to the exhaust ports or diverts it to atmosphere when the system is not active.

When the valve is stuck open, air continues to be injected into the exhaust even when the system should be off. This can cause a lean exhaust condition during closed-loop fuel control, potentially triggering upstream oxygen sensor codes and driveability issues. The PCM monitors the system by observing the oxygen sensor response when the SAI pump is commanded on and off; failure to see the expected sensor shift indicates a performance or stuck-valve fault.

Diagnosis involves verifying whether the valve is mechanically stuck, has a failed actuator, or is receiving an incorrect command from the PCM. Carbon buildup from exhaust backflow through a failed check valve can jam the switching valve in the open position and is a common failure mode on high-mileage engines.

Common causes

Most-frequently reported root causes when P2435 is logged.

  • 1
    Carbon or debris buildup jamming the switching valve in the open position.
  • 2
    Failed switching valve actuator (electric or vacuum) unable to close the valve.
  • 3
    Collapsed or perforated vacuum hose preventing valve closure on vacuum-operated systems.
  • 4
    Faulty check valve allowing exhaust backflow that deposits carbon on the switching valve.
  • 5
    PCM output driver fault continuously commanding the valve open.
  • 6
    Wiring short keeping the valve solenoid energized when it should be off.

Symptoms drivers notice

MIL illuminated with P2435 stored.
Lean oxygen sensor readings or fuel trim corrections during SAI-off conditions.
Possible rough idle or hesitation caused by unintended air injection into the exhaust.
Companion codes for oxygen sensor performance or fuel trim faults may also be set.

How to diagnose P2435

A typical diagnostic flow when this code is present.

  1. 1
    Retrieve all DTCs and note any oxygen sensor or fuel trim codes stored alongside P2435.
  2. 2
    Inspect the switching valve for carbon buildup or mechanical jamming; attempt manual actuation.
  3. 3
    Check vacuum hoses for cracks or collapse on vacuum-operated valve actuators.
  4. 4
    Verify the check valve integrity to prevent exhaust backflow contamination.
  5. 5
    Command the SAI system on and off with a scan tool while monitoring O2 sensor response for expected lean/rich shift.
  6. 6
    Inspect the switching valve electrical connector and wiring for shorts to voltage.
  7. 7
    Replace the switching valve assembly if it fails to close when commanded off and wiring checks pass.

Related powertrain codes

Frequently asked questions

Does P2435 affect emissions significantly?

Yes, a stuck-open valve causes unintended air injection that disrupts closed-loop fuel control and can increase tailpipe emissions during normal warm-up driving.

Can I drive with P2435?

The vehicle is usually driveable, but fuel trim disturbances caused by the stuck valve can worsen fuel economy and may set additional O2 sensor codes over time.

What is Bank 1?

Bank 1 refers to the side of the engine that contains cylinder number 1; on inline engines there is only one bank.

Is P2435 common on high-mileage engines?

Yes, carbon accumulation from exhaust backflow through aging check valves is a frequent cause of SAI switching valve sticking on older vehicles.

Disabling P2435 in software

RaceTune can permanently disable P2435 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

ECUs with a P2435 disable in our catalogue

Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.

  • Bosch EDC17C56 verified 1 software version

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

Got P2435 in your scan?

Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.

Upload your file