The evap pressure sensor is out of range. The evap system captures petrol vapour from the tank, so this is an emissions fault rather than a drivability one.
P0450 — also written PO45O, P 0450, 0450 — is the OBD-II code for evaporative emission system pressure sensor malfunction. Same code, same fix: this page covers every spelling of it.
P0450 is a emissions fault code, typically costing £25–£350 to put right in a UK garage.
What causes P0450?
- Failed evap pressure sensor
- Loose or cracked fuel filler cap
- Split evap hose over the tank
- Corroded connector
How P0450 is fixed
- Fit a new filler cap first — it fixes a surprising number of these
- Smoke-test the evap system
- Replace the pressure sensor
P0450 repair cost in the UK
Most P0450 repairs land between £25–£350 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Can you drive with P0450?
Yes, but the engine light will fail an MOT on cars first used from 2018.
Urgency: low.