P0426

Catalyst Temperature Sensor Circuit Range/Performance Bank 1 Sensor 1

Q: Is it safe to drive with P0426?

Generally yes. It's an emissions-monitoring fault, so plan to fix it before an emissions test. If it stems from an actual exhaust over-temperature, address that cause promptly.

Q: Can I just clear P0426?

It returns once the ECM again sees the sensor out of range. Repair the sensor or wiring first, then clear and re-test.

Emissions / catalyst Generic OBD-II Medium

What it means

P0426 means the bank 1 catalyst temperature sensor is reporting a value that doesn't match expected conditions. This sensor monitors catalytic converter temperature. An out-of-range reading — usually from a failing sensor or wiring issue, and occasionally from a real exhaust over-temperature — sets the code, typically without any obvious change in how the car drives.

Medium

Can I keep driving? Safe to drive. This mainly affects emissions monitoring; there's usually no drivability problem, but it can fail an emissions test.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Often no noticeable change in how the vehicle drives
May fail an emissions/readiness test
Possible loss of power only if the ECM limits output to protect the catalyst

Common causes

Most likely first

Faulty catalyst temperature sensor reading out of rangeLikely
Damaged or corroded wiring in the sensor circuitCommon
Loose or corroded connectorCommon
Actual exhaust over-temperature (e.g. from a misfire) the sensor is correctly reportingLess often
Failed ECM (rare)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and note the catalyst temperature being reported.
Inspect the sensor connector and wiring for damage or corrosion.
Compare the reading to actual conditions to see if the sensor or the exhaust is the problem.
Rule out misfire or rich/lean codes that could genuinely overheat the catalyst.
Replace the catalyst temperature sensor if it reads out of range. Clear and re-test.

FAQ

Quick answers

Is it safe to drive with P0426?+

Generally yes. It's an emissions-monitoring fault, so plan to fix it before an emissions test. If it stems from an actual exhaust over-temperature, address that cause promptly.

Can I just clear P0426?+

It returns once the ECM again sees the sensor out of range. Repair the sensor or wiring first, then clear and re-test.

Read & clear P0426 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX