4-Pin 1-965261-1 / 144998-1 Sealed Male & Female Connector – AMP Oxygen Sensor & Starter Harness

Direct-fit replacement for TE Connectivity / AMP part numbers 1-965261-1 (male plug) and 144998-1 (female socket), a 4-pin sealed connector pair used for oxygen sensor harness connections and starter motor wiring on automotive applications. The AMP sealed series provides robust IP68 protection for underbody and exhaust-adjacent sensor locations.

Key Specifications

• OEM Part Numbers: 1-965261-1 (male) / 144998-1 (female)
• Pin Count: 4
• Seal Type: Fully sealed (IP68)
• Wire Gauge: 18 AWG (0.5 mm²)
• Wire Length: 5.5 inches (140 mm)
• Housing Material: PA66 glass-filled nylon
• Terminal Material: Copper alloy, tin-plated
• Current Rating: Up to 13A per pin
• Operating Temperature: -40°C to +125°C

Applications

• Wideband oxygen (O2) sensor harness: 4-pin wideband lambda sensor connector (heater + signal circuits)
• Starter motor relay harness: 4-pin starter control and power circuit connector
• Exhaust gas temperature (EGT) sensor: Turbo and diesel engine EGT sensor wiring
• Fuel injector harness: 4-pin injector connector on some European OEM platforms

4-Pin O2 Sensor – Pin Assignment

Fault Codes Linked to O2 Sensor Connector Failure

• P0030 / P0050 – O2 Sensor Heater Control Circuit (Bank 1/2, Sensor 1)
• P0031 / P0051 – O2 Sensor Heater Circuit Low (open at Pin 1 or 2)
• P0131 / P0151 – O2 Sensor Circuit Low Voltage
• P0136 / P0156 – O2 Sensor Circuit (Bank 1/2, Sensor 2)

Frequently Asked Questions

Q: What is the difference between 1-965261-1 and 144998-1?
A: 1-965261-1 is the male plug housing (harness side); 144998-1 is the female socket housing (sensor side). For O2 sensor replacement, you typically need the female socket (144998-1) which connects directly to the sensor body.

Q: Can a bad O2 sensor connector cause a rich or lean condition?
A: Yes. An open circuit at the O2 sensor connector causes the ECM to lose lambda feedback and default to open-loop fueling, which typically results in a rich condition (P0172 / P0175) and increased fuel consumption.

Q: What crimping tool is needed?
A: Use a ratchet crimper rated for 18 AWG (0.5 mm²) AMP sealed terminals – Engineer PA-09 or equivalent precision ratchet crimper.

Package Contents

1 × 4-Pin Male Connector (1-965261-1) with 18 AWG wire
1 × 4-Pin Female Connector (144998-1) with 18 AWG wire and terminal inserts