What Does P242B Mean?
The exhaust gas temperature (EGT) sensor 3 on bank 1 is reading values outside the expected range or responding too slowly compared to other sensors. This sensor typically monitors temperature after the catalytic converter or diesel particulate filter.
Common Causes
45%
Failed or degraded EGT sensor
30%
Wiring harness damage, corrosion, or poor connections at sensor connector
15%
Exhaust leaks affecting sensor readings
10%
ECM software calibration issue or ECM fault
Diagnostic Steps
1
Step 1: Visually inspect EGT sensor 3 and wiring for damage, corrosion, or loose connections
2
Step 2: Check sensor resistance and voltage signal against manufacturer specifications using multimeter
3
Step 3: Compare live data from EGT sensor 3 with other EGT sensors during warm-up and operation
4
Step 4: Inspect exhaust system for leaks near sensor location
5
Step 5: Replace sensor if readings are out of specification or erratic
Estimated Repair Cost
$200 - $500
Parts + labor, varies by vehicle and location
The exhaust gas temperature (EGT) sensor 3 on bank 1 is reading values outside the expected range or responding too slowly compared to other sensors. This sensor typically monitors temperature after the catalytic converter or diesel particulate filter.
The most common cause of P242B (Exhaust Gas Temperature Sensor Circuit Range/Performance Bank 1 Sensor 3) is: Failed or degraded EGT sensor
Typical repair costs for P242B range from $200 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is safe to drive but may enter reduced power mode. Extended operation may damage emission control components.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P242B to identify the root cause.
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Quick Info
Category
Powertrain
System
Emissions Control
Difficulty
Type
Generic (SAE)
Recommended Tools
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