Oxygen Sensor Replacement
Also called O2 sensor change
The oxygen sensor sits in the exhaust and tells the engine computer whether the fuel mixture is rich or lean, so the computer can adjust fuelling. A lazy or dead sensor costs fuel, causes rough running and keeps the check engine light on. Replacement fits a new sensor and clears the fault. It will not fix poor mileage caused by a vacuum leak, dirty injectors or low tyre pressure, so we confirm the sensor is genuinely at fault first.
Signs you need this
- Check engine light with an oxygen sensor or fuel trim code
- Fuel average dropping noticeably over a few weeks
- Rough or uneven idle, particularly when cold
- Hesitation when pulling away from a stop
- Strong fuel smell from the exhaust
Not all of these have to be present, and one of them on its own can mean something else entirely. That is what the diagnosis is for.
What the job includes
- Scanning to identify which sensor is reporting the fault
- Checking live sensor readings against expected switching behaviour
- Inspecting for exhaust leaks and wiring damage that mimic sensor failure
- Removing the seized sensor and fitting the correct replacement
- Clearing codes and confirming normal fuel trim on a road test
How we do it
Scan and identify
The fault code tells us which sensor and which bank, but not yet whether the sensor or its circuit is at fault.
Test before replacing
We watch the sensor's live signal and check its heater circuit and wiring, so a good sensor is not thrown away.
Replace the sensor
The old sensor is heated and extracted carefully to protect the threads, and the correct type is fitted with anti-seize.
Verify the fix
Codes are cleared and we road test while watching fuel trims to confirm the engine is now correcting properly.
How we work
The same on every job, which is why we can write it down.
Diagnosis before quote
We find the fault first. A price given over the phone for a noise nobody has heard is a guess.
The price is agreed first
You approve the work and the cost before a spanner is picked up. Extra work means another call.
Parts you can check
We tell you whether a part is genuine, OEM, aftermarket or used, and what each one costs.
Old parts returned
Ask and we will hand back whatever we replaced. It is the simplest proof that the job was done.
Book oxygen sensor replacement
Fill this in and a person will call you back to confirm the time and the price. Only your name and one way to reach you are required.
You send this
Takes a minute. No payment, no obligation.
We call you
To confirm the car, the time and the location.
Tell us the car and the symptom
We will arrange a mechanic at your location, or a slot at the nearest workshop. No payment until the price is agreed.