Engine-Codes - Mercury - P1129 MERCURY

P1129 MERCURY - Downstream Oxygen Sensors Swapped from Bank to Bank

Repair Importance Level: 3/3
Repair Difficulty Level: 2/3  What is this?
Table of contents

P1129 MERCURY Possible Causes

    Crossed HO2S harness connectors (downstream) Crossed HO2S wiring at the harness connectors (downstream) Crossed HO2S wiring at the 104-pin harness connectors (downstream)

How is the P1129 MERCURY code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

What is the cost to diagnose the P1129 MERCURY code

Labor: 1.0

The cost to diagnose the P1129 MERCURY code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
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Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P1129 MERCURY Meaning

The heated oxygen sensor (HO2S) monitor determines if the HO2S signal response for a fuel shift corresponds to the correct engine bank. The test fails when a response from the HO2S being tested is not indicated.

More Information

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