What Does P242A Mean?
The exhaust gas temperature sensor circuit for Bank 1 Sensor 3 (typically located downstream of the catalytic converter) has a malfunction. This sensor monitors exhaust temperature for emissions control and component protection.
Common Causes
40%
Failed exhaust gas temperature sensor
30%
Damaged or corroded sensor wiring or connector
15%
Sensor contaminated by oil, coolant, or carbon deposits
10%
Open or short circuit in sensor wiring
5%
PCM sensor circuit failure
Diagnostic Steps
1
Step 1: Locate EGT Sensor 3 on Bank 1 (typically post-catalyst position) and inspect for physical damage
2
Step 2: Check sensor connector for corrosion, moisture, or loose connection
3
Step 3: Measure sensor resistance and compare to specifications at ambient temperature
4
Step 4: Test voltage signal at PCM connector while monitoring sensor data
5
Step 5: Check for exhaust leaks near sensor that could affect readings
Estimated Repair Cost
$150 - $600
Parts + labor, varies by vehicle and location
The exhaust gas temperature sensor circuit for Bank 1 Sensor 3 (typically located downstream of the catalytic converter) has a malfunction. This sensor monitors exhaust temperature for emissions control and component protection.
The most common cause of P242A (Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 3) is: Failed exhaust gas temperature sensor
Typical repair costs for P242A range from $150 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive but should be repaired soon. Loss of temperature monitoring can prevent detection of dangerous overheating conditions.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P242A to identify the root cause.
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Quick Info
Category
Powertrain
System
Exhaust System / Emissions
Difficulty
Type
Generic (SAE)
Recommended Tools
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