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The throttle body regulates the air entering the engine: when it gets encrusted, the idle becomes rough and the car can stall on deceleration. After cleaning, an adaptation with the diagnostic tool is always needed, otherwise the symptoms remain.

Typical symptoms

• High, low or hunting idle
• Stalling on deceleration or when braking
• Delayed throttle response
• Engine light with throttle position faults
• Limp mode with limited revs

Causes

• Carbon deposits from crankcase vapours and the EGR
• Worn potentiometer or electric motor
• Corroded connector or damaged wiring
• Air leaks in the ducts downstream

Cleaning done properly

• Removal and cleaning with a specific product, without forcing the throttle by hand
• Checking the position values with the throttle closed and open
• Adaptation and parameter reset with the diagnostic tool at the end

How MasterTuning helps

We check the component with real measurements, not by elimination: flow rates, pressures, corrections and signals read directly from the ECU. We repair, replace and recalibrate the software when needed. Centres throughout Italy.

Read more: vehicle database · what is ECU remapping · find an installer

Want an accurate diagnosis? Contact MasterTuning and book at your nearest centre.

Frequently asked questions

Is a reset needed after cleaning the throttle body?

Yes: without the adaptation with the diagnostic tool the ECU keeps using the old values and the idle stays rough.

Can the throttle body be cleaned without removing it?

Intake sprays give partial results; effective cleaning is done by removing the throttle body.

Can the throttle body make the car stall?

Yes: if the throttle does not regulate the air correctly at idle, the engine can stall on deceleration.