DOBD DashX Browse all codes Blog
P042D

Catalyst Temperature Sensor Circuit High Bank 1 Sensor 2

Catalyst temperature sensor (emissions) Generic OBD-II Medium

What it means

P042D means the bank 1, sensor 2 catalyst temperature sensor circuit is reading high — usually an open circuit or a short to voltage. This sensor lets the ECM monitor converter temperature; a high, out-of-range reading sets the light but generally doesn't change how the engine starts or drives.

Medium

Can I keep driving? Safe to drive — this is a sensor-circuit fault that mainly turns on the warning light and affects emissions monitoring, not how the car runs.

Real-world scan data

Seen in
24
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

Common causes

Most likely first

  1. Sensor wiring open or shorted to voltage
  2. Faulty catalyst temperature sensor (bank 1, sensor 2)
  3. Poor or corroded connector
  4. ECM fault (rare)

How to diagnose & fix

Work through it in order

  1. Read freeze-frame data and inspect the sensor connector and wiring for an open or a short to voltage.
  2. Measure the sensor's resistance/signal against temperature.
  3. Replace the temperature sensor if it is out of spec.
  4. Repair the wiring or connector as needed.
  5. Clear the code and re-test.

FAQ

Quick answers

Is it safe to drive with P042D?+
Yes — it's a monitoring-sensor fault, so fix it to clear the light and pass emissions.
Can I just clear P042D?+
You can, but it returns until the sensor circuit is repaired.

Related codes

Read & clear P042D 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