Problems of the catalytic converter: symptoms, cost and affected models
We have documented 6 faults of the catalytic converter in 4 engines and 1 car, affecting 27 models of car in our database. The most important by severity and frequency: faulty catalytic converter and lambda sensors on the 2005-2010 Swift (engine warning light) (1.3, 1.5 and 1.6 gasolina (serie M)), piston and connecting rod damage from catalytic converter overheating in the naturally aspirated 1.6 GDI (1.6 GDI / T-GDI) and gearbox wiring harness with insufficient clearance from the catalytic converter (Jeep Wrangler JL).
How it works and why it fails
Catalytic converter
The catalytic converter turns the most polluting exhaust gases into less harmful ones. On diesels it usually sits alongside the particulate filter. It fails mostly as a consequence of another problem: misfires, oil consumption or a poorly adjusted mixture that overheat or clog it.
What to do
The typical warning is the engine light with code P0420 (catalyst efficiency below threshold). Before replacing it, find the cause: if the engine burns oil or misfires, a new converter will not last long. A blocked converter robs power and can overheat the exhaust.
General explanation by MotorFiable. The specific faults of each engine and car, with their sources, are on the linked pages.
Common symptoms
The symptoms that come up most often in the documented faults of the catalytic converter. Open each one to see what other faults cause it.
Problems of the catalytic converter by engine
From most to least important (severity × frequency). Each page details the affected versions and years, symptoms, cost and how to check for it.
- 1Medium severityFrequency: Common1.3, 1.5 and 1.6 gasolina (serie M)Faulty catalytic converter and lambda sensors on the 2005-2010 Swift (engine warning light)On the 2005-2010 Swift the catalytic converter often fails at around 50,000 km according to gebrauchtwagenberater.de, and several 1.6 owners cite the lambda sensor. The warning is the engine light; on the Sport the catalytic converter is integrated with the manifold.
- 2Critical severityFrequency: Rare1.6 GDI / T-GDIPiston and connecting rod damage from catalytic converter overheating in the naturally aspirated 1.6 GDIIn the US, Kia recalled the 2012-2016 Soul with the naturally aspirated 1.6 GDI: a catalytic converter that overheats can disturb combustion and damage pistons, with a risk of breaking a connecting rod and puncturing the block. We have not found an equivalent warning for this engine in European cars.
- 3Low severityFrequency: Occasional1.0 VVT-iFaulty lambda sensor (P0420 code) on the 1.0 VVT-iOn the 1.0 VVT-i (1KR-FE) in the Aygo, C1 and 107/108, the lambda sensor, especially the one upstream of the catalytic converter, is documented as failing at high mileage and leaving code P0420 and the engine warning light. It is a cheap repair and does not damage the engine.
- 4Low severityFrequency: Rare1.6 16v HR16DE / H4MNo documented pattern of chain, catalytic converter or coil failuresUnlike other turbo engines from the same alliance, the sources consulted do not document a pattern of timing chain, catalytic converter or ignition coil failures for this naturally aspirated block: across more than 100 combined accounts, these sections appear empty or, at most, with an isolated case.
- 5Low severityFrequency: Rare1.3, 1.5 and 1.6 gasolina (serie M)Loose catalytic converter substrate on the SX4 1.5 and 1.6 (2008 campaign)In April 2008 Suzuki recalled the 1.5 and 1.6 petrol SX4s built between January 2006 and December 2007 to inspect the catalytic converter, whose substrate could come loose and cause rattling noises and higher emissions. The inspection was free.
Engines with faults of the catalytic converter
Problems of the catalytic converter by car
Faults documented on specific cars, which occur with any engine. From most to least important.
Problems of the catalytic converter in your car
4 cars have several documented faults of the catalytic converter. Choose yours to see only the ones that affect them, by engine and by year.
Frequently asked questions
Which engines have the most faults of the catalytic converter?
By severity and frequency, the 1.3, 1.5 and 1.6 gasolina (serie M) (faulty catalytic converter and lambda sensors on the 2005-2010 Swift (engine warning light), medium severity), the 1.6 GDI / T-GDI (piston and connecting rod damage from catalytic converter overheating in the naturally aspirated 1.6 GDI, critical severity), the 1.0 VVT-i (faulty lambda sensor (P0420 code) on the 1.0 VVT-i, low severity) and the 1.6 16v HR16DE / H4M (no documented pattern of chain, catalytic converter or coil failures, low severity).
Which cars have problems of the catalytic converter?
Among those we have analysed: Jeep Wrangler JL (gearbox wiring harness with insufficient clearance from the catalytic converter).
What symptoms does a fault of the catalytic converter cause?
The most frequently cited in the documented faults: engine fault warning light (check engine), "pollution control system faulty" message, deep metallic engine knock, engine stalls or cuts out while driving, increase in fuel consumption and metallic timing noise on start-up.