OBD-II Generic Error Code P2042: How to Fix It

Medium 30-60 minutes Medium Severity Verified July 2026
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Error Code
P2042
Brand
OBD-II Generic
Product Type
automotive
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
30-60 minutes
Error code P2042 indicates that the exhaust gas temperature sensor for bank 2, sensor 2 is reporting a voltage higher than expected. This typically points to a faulty sensor, wiring issue, or exhaust system problem. Ignoring it may lead to reduced fuel efficiency and potential damage to the catalytic converter or DPF.
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Tools You'll Need

How to Fix Error Code P2042

  1. Read and Confirm the Code

    Ensure the vehicle is off before connecting the scanner.

  2. Inspect the Exhaust Gas Temperature Sensor (EGT) B2S2

    Allow the exhaust system to cool completely before touching any components.

  3. Check Wiring and Connector

    Disconnect the battery before testing resistance to avoid short circuits.

  4. Test the Sensor Voltage and Resistance

    Use proper multimeter settings to avoid damaging the ECU.

  5. Replace the EGT Sensor

    Do not over-tighten; use a torque wrench if possible.

  6. Clear Codes and Test Drive

Parts You May Need

Exhaust Gas Temperature Sensor (EGT) B2S2
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Exhaust Gas Temperature Sensor (EGT) B2S2
Check Price on Amazon
Exhaust Gas Temperature Sensor (EGT) B2S2
Check Price on Amazon
Exhaust Gas Temperature Sensor (EGT) B2S2
Check Price on Amazon
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When to Call a Professional

If you are not comfortable working with exhaust systems or electrical diagnostics, or if the code persists after sensor replacement, a professional mechanic should inspect for exhaust leaks, ECU issues, or wiring harness damage.

Frequently Asked Questions

Can I drive with error code P2042?
You can drive short distances, but it may reduce fuel economy and cause damage to the catalytic converter or DPF over time. It's best to fix it promptly.
Where is the exhaust gas temperature sensor B2S2 located?
Bank 2 refers to the side of the engine opposite the #1 cylinder (usually passenger side on transverse engines). Sensor 2 is downstream of the catalytic converter or DPF, typically on the exhaust pipe.
How much does it cost to fix P2042?
DIY cost for a new EGT sensor ranges from $50-$150. Professional repair including labor may cost $200-$400.
What causes the EGT sensor to fail?
Common causes include excessive heat, contamination from oil or fuel, physical damage from road debris, or age-related wear.
Will clearing the code fix P2042 permanently?
Clearing the code only removes the warning. If the underlying issue is not fixed, the code will return. Always diagnose the root cause.

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