Porous PTFE Filter - Allows atmospheric oxygen to enter the sensor without permitting water or engine contaminants to seep into the casing.
3
Double Protection Cover - Maintains proper unit temperature for quicker response times and protects the ceramic element against silicone and lead poisoning.
4
Stainless Steel Housing - Resists corrosion and contamination with a rugged, watertight body and maximizes engine performance and fuel efficiency while reducing fuel consumption and harmful emissions
5
Aluminum-Oxide Trap Layer - Keeps silicone and lead outside the ceramic element through DENSO's exclusive design, preventing damage to the platinum electrode.
O2 Sensor Identification Guide
An OBD Scan Tool will usually identify Oxygen Sensors by the Bank Number (B1 = Bank 1) and Sensor Number (S1 = Sensor 1). Bank 1 will always contain Cylinder 1, which is located closest to the front of the engine.
Part manufacturers often use different terms than scan tools to identify sensor positions. Regardless of the vehicle's engine orientation, the right or left bank is determined by viewing the engine from the rear (opposite the drive belts).
A
Upstream Sensor (Before Converter)
B
Downstream Sensor (After Converter)
C
Left or Front Upstream Sensor (Before Converter)
D
Right or Rear Upstream Sensor (Before Converter)
Common O2 Sensor Contaminants
Oxygen (O2) Sensors commonly fail due to contamination. When checking or replacing an O2 Sensor, visually inspect the sensor body to determine if it has been contaminated by a faulty part or substance upstream, and correct the fault before replacing the sensor.
ANTIFREEZE POISONING
Common Causes:
Cracked or warped cylinder head
Leaking cylinder head gasket
Leaking intake manifold gasket
Antifreeze Poisoned O2 Sensor
SILICONE POISONING
Common Causes:
Use of an improper silicone gasket sealant on the engine
O2 Sensor Identification Guide
Common O2 Sensor Contaminants
