P0474 on Audi: Exhaust Pressure Sensor Intermittent
Diagnostic trouble code P0474 on Audi vehicles — what it means, the common
causes, and how to confirm the real fault before replacing parts.
What does P0474 mean?
P0474 indicates: Exhaust Pressure Sensor Intermittent.
This relates to the Emissions / auxiliary emission controls system.
Common causes of P0474
Faulty pressure sensor
Blockage upstream of secondary air pressure sender G609
Restricted flow downstream of pressure sensor causing pressure level increase
Leak in the system causing pressure level decrease
What to check (live data)
Signal from secondary air injection sensor G609 compared with ambient pressure sensor signal
Signal from secondary air injection sensor G609 compared with intake manifold pressure signal
Pressure level during secondary air diagnosis phases
Parts often involved in P0474
Secondary air injection sensor -1 G609
Don't replace parts until the root cause is confirmed — many of these codes are caused by wiring, a connector or an upstream fault, not the part itself.
Get the confirmed root cause for P0474 — on YOUR vehicle
A code is a symptom, not a diagnosis. AutoDX Pro cross-checks several
independent assessments, pinpoints the actual root cause, gives you the
exact tests to confirm it, and shows the parts — only after the cause is
confirmed. Reads your scan-tool photo and decodes your VIN with open
recalls.
P0474 is a diagnostic trouble code: Exhaust Pressure Sensor Intermittent.
What are the common causes of P0474 on an Audi?
Common causes include: Faulty pressure sensor, Blockage upstream of secondary air pressure sender G609, Restricted flow downstream of pressure sensor causing pressure level increase, Leak in the system causing pressure level decrease. The exact cause depends on the vehicle — confirm it before replacing parts.
Can I keep driving an Audi with P0474?
It depends on the fault and your symptoms. Some causes are minor, others can damage components or affect safety. Get the root cause confirmed before deciding.
How do I fix P0474 on an Audi?
Confirm the actual root cause with targeted tests first, then replace only the part that's at fault. AutoDX Pro gives you the root cause, the exact tests, and the parts for P0474 on your specific Audi.