P0438 — Catalyst Temperature Sensor Circuit High Bank 2 Sensor 1

What Does P0438 Mean?

P0438 is a diagnostic trouble code indicating: Catalyst Temperature Sensor Circuit High Bank 2 Sensor 1. This code relates to the emission controls system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P0438

⚠️ Check Engine Light (MIL) illuminated
⚠️ Catalyst Temperature Sensor reading stuck at maximum value
⚠️ Related system operating erratically or in default mode
⚠️ Failed emissions test

Common Causes

🔍 Short to voltage in Catalyst Temperature Sensor wiring harness
🔍 Corroded or water-damaged Catalyst Temperature Sensor connector
🔍 Faulty Catalyst Temperature Sensor outputting maximum voltage
🔍 Damaged wiring rubbing against metal components
🔍 ECM/PCM internal fault (rare)

Frequently Asked Questions

What does P0438 mean?

P0438 indicates: Catalyst Temperature Sensor Circuit High Bank 2 Sensor 1. The vehicle's computer has detected that the Catalyst Temperature Sensor is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P0438?

Yes, P0438 is generally safe to drive with in the short term. However, it should still be addressed to pass emissions testing and prevent potential secondary issues.

How much does it cost to fix P0438?

Repair costs for P0438 typically range from $20 to $300, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.

What To Do Next

Possible Fixes

🔧 Inspect and repair Catalyst Temperature Sensor wiring for short to voltage
🔧 Clean or replace corroded Catalyst Temperature Sensor connector
🔧 Replace faulty Catalyst Temperature Sensor

1
Find your vehicle above
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2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

P0438: Catalyst Temperature Sensor Circuit High Bank 2 Sensor 1