P0435 Catalyst Temperature Sensor Bank 2 Sensor 1

P0435 indicates an issue with Catalyst Temperature Sensor Bank 2 Sensor 1. The controller cannot trust the Bank 2 catalyst temperature feedback.

Code details

Generic OBD-II · P0

System: Emissions
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace the Bank 2 catalyst for P0435 until the temperature sensor circuit has been tested.

Symptoms of P0435

Check-engine light, often with no obvious change in how the car drives.
A failed emissions test or incomplete readiness monitors.
Sometimes a faint fuel-vapour smell (on EVAP codes).

Common causes of P0435

A worn catalytic converter or an oxygen/air-fuel sensor reading out of range.
EVAP leaks — a loose or failed gas cap, cracked hose, or purge/vent valve.
Exhaust leaks, fuel-trim problems, or a fault in a related monitor.

Useful checks before replacing parts

Check Bank 2 Sensor 1 catalyst temperature data, reference voltage, ground, signal wiring, freeze-frame temperature, and related temperature circuit codes.
Inspect connector heat damage, exhaust routing, wiring insulation, corrosion, sensor placement, and signs of impact or contamination.
Compare cold-start and fully warm readings to expected ambient and exhaust temperature behavior.

Related OBD-II codes

These nearby emissions entries can help compare wording and pin down the fault area.