Description
Intake air resonator for Citroën and Peugeot vehicles with 1.8i, 2.0i and 2.2i engines.
Product Overview
This intake air resonator is an OEM-style component manufactured for Stellantis Citroën and Peugeot platforms. Designed to fit a range of 1.8i, 2.0i and 2.2i petrol engines (including applications such as the Peugeot 407), the resonator smooths airflow, reduces intake noise and helps maintain consistent air delivery to the engine. Commonly searched under part numbers 9646767780 and 1427J9, this unit is a direct-replacement item aimed at professional workshops and DIY mechanics who require a reliable, vehicle-specific intake component.
Benefits
- Reduces induction noise and unpleasant resonance during throttle changes.
- Stabilizes airflow to the throttle body and mass air flow (MAF) sensor for smoother idling and throttle response.
- OEM-fit design ensures correct mounting points and sealing to the airbox and intake ducting.
- Direct-fit replacement using original part numbers improves compatibility and reduces installation time.
Technical Information
- Manufacturer: Stellantis / Citroën / Peugeot
- Model: Citroën and Peugeot vehicles with 1.8i, 2.0i and 2.2i petrol engines (e.g. Peugeot 407)
- Product Codes: 9646767780, 1427J9
- Other Numbers: NFP
Installation Recommendations
Recommended for fitment by experienced technicians or competent DIYers. Typical replacement procedure:
- Park vehicle on level ground and allow the engine to cool.
- Remove the engine cover (if fitted) and/or loose intake trim to access the airbox and resonator.
- Loosen hose clamps and remove any retaining clips or screws holding the resonator to the airbox and intake duct.
- Carefully withdraw the resonator from the intake assembly, checking surrounding hoses and connectors for wear.
- Fit the new resonator in the correct orientation, replace seals or clamps as needed and tighten fasteners to the original torque where specified.
- Reinstall any removed covers and perform a visual check for leaks. Start the engine and listen for changes in intake noise and idle quality.
Tip: Inspect the MAF sensor, intake boots and clamps while the resonator is removed. Replace damaged hoses or loose clamps to ensure a long-lasting repair.
Most Common Failure Causes
- Material fatigue and cracking due to heat cycles and engine bay vibration—plastic resonators can develop splits that cause vacuum leaks and increased intake noise.
- Oil contamination from PCV system or turbocharger blow-by (on applicable engines) leading to softening or deforming of the resonator and seals.
- Loose or broken mounting points and degraded rubber seals resulting in air leaks and poor sealing to the airbox.
- Age-related deterioration of internal baffles which can increase intake noise and affect airflow characteristics.
Maintenance And Service Life
There is no fixed interval for replacement. Inspect the resonator during routine service (air filter replacement or when diagnosing intake leaks). Typical signs that indicate replacement is required include audible hissing or sucking noise from the intake, rough idle, or visible cracks/deformation on the resonator body.
Compatibility And Part Numbers
When ordering, reference the product codes listed above (9646767780, 1427J9) to improve the chance of correct fitment. The resonator is intended as a direct replacement for matching Citroën and Peugeot 1.8i / 2.0i / 2.2i engine applications, including models such as the Peugeot 407 where these part numbers apply.
Who Should Fit This Part
Suitable for professional auto technicians and experienced DIY mechanics comfortable working in the engine bay. If you are unsure about removal steps or encounter electronic sensors while accessing the resonator, consult a workshop manual or a qualified technician.
