OBD2 Car ScannerWhat does P033A mean?
P033A stands for Knock Sensor 4 Circuit (Bank 2). The engine computer has detected an ignition problem or a misfire, meaning one or more cylinders are not burning fuel properly.
Powertrain codes cover the engine, transmission and emissions. When the car's computer sees a reading outside its normal range, it stores this code and may turn on a warning light on the dashboard.
Common causes
- Worn spark plugs
- Faulty ignition coil or plug wires
- Clogged fuel injector
- Vacuum leak
- Low compression
What to do
- Read all stored and pending codes with a scanner. Several codes together often point to one cause.
- Note the freeze frame data (speed, temperature, load) recorded when the code was set.
- Inspect the wiring and connectors of the part named in the code for damage, corrosion or looseness.
- Fix the most likely and cheapest cause first, then clear the code and drive to see if it comes back.
Read this code from your own car
Plug in a cheap ELM327 adapter and the app shows every fault code, what it means and how to fix it.
Frequently asked questions
What does P033A mean?
P033A means “Knock Sensor 4 Circuit (Bank 2)”. It belongs to the ignition system or misfire group: The engine computer has detected an ignition problem or a misfire, meaning one or more cylinders are not burning fuel properly.
Is it safe to drive with P033A?
Avoid driving long distances. This kind of fault can cause damage or affect safety, so get it checked as soon as possible.
How do I clear P033A?
Fix the cause, then clear the code with an OBD2 scanner or app. If the fault is still there, the code will come back.
Related codes
- P0336Crankshaft Position Sensor A Circuit Range/Performance
- P0337Crankshaft Position Sensor A Circuit Low Input
- P0338Crankshaft Position Sensor A Circuit High Input
- P0339Crankshaft Position Sensor A Circuit Intermittent
- P033BKnock Sensor 4 Circuit Range/Performance (Bank 2)
- P033CKnock Sensor 4 Circuit Low (Bank 2)
- P033DKnock Sensor 4 Circuit High (Bank 2)
- P033EKnock Sensor 4 Circuit Intermittent (Bank 2)
Code meanings can vary by manufacturer. This page is general guidance, not a repair manual. Always confirm the cause before replacing parts.