Sensor Replacement
Also called sensor change
Modern engines rely on sensors reporting airflow, temperature, oxygen, crankshaft and camshaft position, and throttle angle. A fault code names the circuit, not the part, so a code for an oxygen sensor can be caused by an exhaust leak or a wiring fault instead. We test the sensor signal, its supply and its earth before replacing anything. Replacing a good sensor because of a code wastes money and leaves the real fault in place, which is the most common thing we are asked to correct.
Signs you need this
- Check engine light with a code naming a specific sensor
- Rough idle, poor throttle response or high fuel consumption
- Temperature gauge or fuel gauge reading incorrectly
- The car starts and stalls, or will not start when hot
- A sensor has already been replaced and the fault returned
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
- Fault codes and freeze frame data read and interpreted
- Sensor supply voltage, earth and signal measured live
- Connector and wiring inspected for corrosion, chafing and pin tension
- Comparison of the reading against a known good value or another sensor
- Correct specification sensor fitted and torqued where required
- Codes cleared and a road test confirming the reading is now correct
How we do it
Read the code properly
The code and its freeze frame data are recorded, then read as a circuit fault rather than as a named faulty part.
Test the circuit
Supply, earth and signal are measured at the sensor connector to see whether the sensor or the wiring is at fault.
Compare live values
The live reading is compared against expected values or another sensor, which shows a drifting sensor a code may miss.
Replace only if needed
The sensor is replaced only where testing proves it, and we explain what the tests showed before fitting.
Verify after repair
Codes are cleared and the car is road tested with live data to confirm the reading is correct and the fault stays away.
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 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.