General Motors 4.3L GM Engine — HEGO (Heated Exhaust Gas Oxygen Sensor) Replacement
Repair & overhaul · HEGO sensor
For the General Motors 4.3L GM Engine, from the General Motors service manual.
Before you start
- HEGO is sensitive to silicone based products and can become contaminated - avoid silicone sealers or silicone-lubricated hoses.
Procedure
- Disconnect negative battery cable.
- Locate affected Oxygen Sensor on the three way catalytic converter/muffler assembly (upstream and downstream).
- Disconnect the Oxygen sensor electrical connector.
- Using an Oxygen Sensor socket, remove the Oxygen Sensor.
- Installation: lubricate threads with anti-seize compound GM P/N 5613695 or equivalent, avoiding contamination of the sensor tip.
- Install Oxygen Sensor, torque to 41 N·m (30 ft. lbs.).
- Reconnect electrical connector and negative battery cable.
- Start engine and check for MIL illumination.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Oxygen sensor torque 41 N·m (30 ft. lbs.)
Source: General Motors service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.