Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Component description for O2 sensor - GF07.04-P-6100AMG
ENGINE 156.980 in MODEL 164, 251 up to Model Year 8
O2 sensors before CAT
ENGINE 156.982 in MODEL 209
O2 sensors before CAT
ENGINE 156.983 in MODEL 211, 219
O2 sensors before CAT
ENGINE 156.984 in MODEL 216, 221 up to Model Year 8
O2 sensors before CAT
Location (wideband oxygen sensor)
The O 2 sensors upstream of TWC are bolted into the exhaust pipe upstream of firewall catalytic converter.
Task
The O 2 sensors upstream of TWC (control sensors) detect the residual oxygen content in exhaust gas for the following tasks:
- Lambda control
- Self-adjustment of mixture formation
- Function chain tests
Design
The O 2 sensors upstream of TWC are insulated as voltage free and designed as a planar (flat) wideband oxygen sensors.
The active sensor ceramic consists of a gas permeable ceramic body made of zirconium dioxide. The inner protective tube with several slots protects the ceramic body from mechanical stresses and from temperature jumps.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.