Part explained
Lambda (O2) sensor: replacement, price, symptoms
The lambda sensor measures oxygen in the exhaust and trims fuel injection. A failing sensor adds 10–15% to fuel use and can ultimately damage the catalytic converter. This page covers symptoms, price, and which sensor fits.
By the onderdelen.autos editorial team · Updated
What does the lambda sensor do?
Almost every modern car has at least two lambda sensors: one upstream of the cat and one downstream. The upstream sensor trims the mixture moment-to-moment; the downstream verifies catalyst efficiency. Wear lives in the sensor tip — poisoning or sooting up.
Symptoms
- Fault code P0130 – P0167 (lambda circuit fault).
- Higher fuel consumption (~10% above normal).
- Hesitating acceleration or rough idle.
- Wrong rich/lean reading in a diagnostic tool.
- Eventually: P0420 (downstream of lambda → catalyst overload).
When to replace
Indicative 100,000 – 160,000 km. A fault code is almost always the first indicator.
Typical interval: 100,000–160,000 km
What does a lambda sensor cost?
New: € 60 – € 280 depending on type (narrow-band / wide-band). Used or refurbished: € 20 – € 80. Workshop labour: 0.5 – 1.5 hours.
| Condition | From | To |
|---|---|---|
| New | € 60 | € 280 |
| Used / refurbished | € 20 | € 80 |
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DIY?
Difficulty: Easy
One bolt, one connector. With a cold engine the sensor rarely yields — heat-soak it first (engine off!) before unscrewing.
- Lambda sensor socket (22 mm slotted)
- Extension + ratchet
- Optional: a torch for seized fittings
Frequently asked questions
Which sensor is faulty — upstream or downstream?
P013x = upstream. P014x / P015x = downstream.
Can I use a universal lambda sensor?
Often yes, but you must splice the connector. Vehicle-specific is easier.
What is a wide-band sensor?
Higher-resolution sensors — standard on modern direct-injection engines.
Workshop replacement cost?
€ 100 – € 400 including the part.
Can a faulty sensor damage [[topic:katalysator|my catalyst]]?
Yes — chronic rich mixture overloads the honeycomb.
Related parts
Lambda sensors from Dutch inventory
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