A dirty throttle body makes idle hunt and can stall the car at traffic lights. It is cleaned, but on almost all modern cars adaptation in diagnosis is needed afterwards, otherwise the problem returns.
Symptoms
- Unstable idle, too high or too low
- Jerking on lift-off and pulling away
- Car stalls at traffic lights or when manoeuvring
- Delayed throttle response
- Check engine light (throttle errors)
Why it gets dirty
Oil vapour from the crankcase breather and recirculated gases (EGR) leave deposits around the throttle plate and idle bore, altering the air flow measured by the control unit.
How it is cleaned
- Removal of the throttle body (or cleaning in place with a specific product).
- Cleaning of the plate and duct without forcing the electric actuator.
- Refit and adaptation of end-stop values in diagnosis.
- Road test and idle check.
Why adaptation is needed
The control unit has memorised the position of the "dirty" throttle. Once cleaned, flow changes: if adaptations are not repeated, idle stays abnormal and the car can keep stalling.
How much does it cost to fix?
| Work | Indicative cost |
|---|---|
| Cleaning + adaptation | €80-200 |
| New throttle body + adaptation | €250-700 |
Figures are indicative market ranges, useful for orientation: the real cost depends on model, engine, parts chosen and labour hours. For an exact quote we need the vehicle registration number.
How MasterTuning helps
We read the real values of the control unit, not just the code: that is the difference between finding the faulty component and replacing parts by trial and error. After the repair we clear the error and check that it does not come back. Find the nearest centre or contact us.
Is idle unstable or does the car stall? Book a diagnosis at the nearest MasterTuning centre.
Frequently asked questions
How often should the throttle body be cleaned?
There is no fixed interval: it depends on use; with evident symptoms it is cleaned.
Is adaptation needed after cleaning?
Yes, in most cases: without it idle may stay abnormal.
Can it be cleaned at home?
It can be removed, but without a diagnostic tool adaptation is not done: better to use a workshop.
How much does it cost to clean?
Roughly €80-200 with adaptation.
