Item Description:

* The oxygen sensor is used to control the air intake, fuel supply, injector, electronic control unit, control sensor, catalytic converter, exhaust gas, diagnostic sensor and other circuits.The oxygen sensor in the car is located in the exhaust manifold and is used to detect exhaust components (including oxygen!) and mainly monitor the performance of the car.

Item Features:

1. Double insulation protective cover can reduce the wear degree of zirconium sensor.
2. Laser welding the sensor body to prevent the entry of contaminants.
3. The internal ceramic insulation allows the sensor to exert its best performance.
4. Sealed wires protect electronic signals from moisture interference.
5. Reference Part Number:234-4018+234-4285
6. 1 x Oxygen Sensor Fit For Upstream Sensor 1 (234-4018)
7. 1 x Oxygen Sensor Fit For Downstream Sensor 2 (234-4285)

Applicable Model:

2002-2003 Chevrolet Trailblazer 4.2L
2002-2003 Chevrolet Trailblazer EXT 4.2L
2002-2003 GMC Envoy 4.2L
2002-2003 GMC Envoy XL 4.2L
2003 Isuzu Ascender 4.2L
2002-2003 Oldsmobile Bravada 4.2L

What are the symptoms of an oxygen sensor going bad?

* Here are some of the most common signs that your oxygen sensor is bad.

1. Check Engine Light comes on--The first line of defense is the Check Engine Light. The Check Engine Light will illuminate if you have a bad or failing oxygen sensor.
2. Bad gas mileage and rotten egg smell--If the oxygen sensor is going bad, the fuel-delivery and fuel-combustion systems will be thrown off. This excess fuel in the engine can produce a sulfuric, rotten egg smell, and may even produce black smoke from the exhaust.
3. Rough engine idle and misfires--Since the oxygen sensor output helps control engine timing, combustion intervals, and the air to fuel ratio, a bad sensor can disrupt these engine functions, causing a rough or irregular engine idle and other engine-related issues.