Cheap Alfa Romeo 156 Catalytic Converter

The 156 ran from 1997 to 2003 (Series 1) before a facelift produced the Series 2 from 2003 to 2007, and whether a cat crosses that boundary depends heavily on the engine code fitted to your specific car. Both generations shared some engines but there were updates to emissions equipment around the facelift, so a visually similar cat from the wrong side of 2003 may not fit correctly or could cause MOT issues. Give your registration and the donor car's registration to the breaker and ask them to match on engine code before buying.

No — petrol and diesel exhaust systems are entirely different, and the catalytic converter is not interchangeable between the two fuel types. Diesel 156s use a different emissions setup to petrol versions, so you must source a cat matched to your exact fuel type. Always quote your fuel type and engine code to the breaker.

No — trim level (whether your 156 is a Turismo, Veloce, Sportwagon or any other variant) does not affect catalytic converter fitment. What matters is the engine code and fuel type, not the spec of the interior or the badging on the boot. Focus on matching the engine code and year rather than worrying about trim.

Yes — all petrol-engined Alfa Romeo 156 models were fitted with a catalytic converter as standard, and diesel variants have their own emissions control equipment in the exhaust system. The 156 was sold throughout a period when catalyst fitment was mandatory for petrol cars under European emissions regulations, so every petrol 156 left the factory with one. If you drive a diesel 156, confirm with the breaker exactly what emissions part you need, as the setup differs from the petrol cat.

The JTS and Twin Spark are different engines with different engine codes, so their catalytic converters are not the same part even though both are 2.0 petrol units. The 2004 Series 2 facelift also falls on the later side of the 2003 model boundary, adding another reason to be cautious about mixing parts across that line. Confirm the exact engine codes of both vehicles with the breaker before proceeding.

Appearances can be misleading with exhaust parts — a cat from a different engine variant or a different emissions era may look similar but fail to fit properly or could cause your car to fail its MOT. The key factors are the engine code and the year, not the visual shape of the unit. Always have the breaker cross-reference both the donor vehicle's and your vehicle's registration and engine codes before committing to a purchase.