All of our ceramic catalytic converters carry a 2 year manufacturers
warranty and metallic catalytic converters carry a 3 year manufacturer
warranty. Although every effort is made to ensure our catalytic
converters will not fail, sometimes a problem with the vehicle will
cause them to break down. The following problems are not covered by our
This is external damage caused to the catalytic converter by hitting
solid objects in the road, i.e. speed ramps. Large rocks etc.
Plugged or Contaminated
Plugged or contaminated catalytic converters are caused by using the
wrong sort of fuel in your car. Using leaded or lead replacement fuel
will plug up the monolith and cause it to stop working. A similar thing
will happen if fuel additives are used that are not suitable for use
with a catalytic converter.
This is caused by oil getting into the exhaust system and contaminating
the catalytic converter. The most likely cause would be a failing seal
The monolith is usually broken when it is impacted by an object or when
it suffers a sudden change in temperature. If the catalytic converter
suffers road damage the monolith inside can be cracked due to it being
crushed by movement of the steel can.
The use of exhaust paste before the catalytic converter can cause the
monolith to break. When the exhaust paste has hardened small pellets may
break away and shoot into the catalytic converter. The monolith will
gradually be destroyed by these pellets and break down. The catalytic
converter can also be damaged by excessive engine vibration.
There are many problems that can cause the catalytic converter to
overheat or fail. The most common cause is unburned fuel entering the
catalytic converter. Faulty spark plugs or ignition leads will cause the
engine to misfire sending unburned fuel into the catalytic converter
leading to overheating and failure.
a) Oxygen Sensor
b) Fuel Injection Systems
If a fuel injector is leaking internally or dribbling fuel into the
engine the excess fuel will enter the exhaust system causing the
catalytic converter to overheat and fail.
c) Map Sensors
Map Sensors tell the electronic control unit the load the engine is
under and the amount of fuel entering it. If a map sensor fails it
causes the engine to run too rich which causes the catalytic converter
to overheat and fail.
d) Carburettor Systems
A worn or defective carburettor can cause a catalytic converter to
overheat and fail. Problems such as improper float or air/fuel mix
adjustments, worn metering rods or a faulty choke system can cause too
much fuel to enter the engine and then the exhaust system causing the
catalytic converter to overheat and fail.
e) Canister Purge Valve Control
This vacuum operated valve vents fuel vapour from the carburettor bowl
to the charcoal canister. If the vacuum is breached the charcoal
canister will flood causing the air/fuel mixture to become too rich
which will cause the catalytic converter to overheat and fail.
If you think your catalytic converter is faulty
If you have reason to believe your catalytic converter is faulty your
first contact must be to our technical department to explain the
problems you are experiencing. If your vehicle has failed the MOT
emissions test you will need to scan and email the emissions report to email@example.com. If your catalytic converter is rattling you will need to get an emissions report completed and scan and email the report to firstname.lastname@example.org.
If necessary (no emissions report supplied) the catalytic converter
will need to be removed and returned to the manufacturer. On arrival at
the manufacturer the catalytic converter will be thoroughly inspected to
establish if a warranty claim is justified.
Blocked Diesel Particulate Filter
A recently fitted DPF that has become blocked is not covered by our warranty. The ONLY reason that a recently fitted DPF will become blocked is because the fault that caused the original filter to block was not rectified prior to fitting the replacement, or an appropriate diagnostic tool was not used to reset the ECU correctly after installation.
A DPF can also become blocked if a related component fails preventing the regeneration process from initiating or just because the type of driving does not allow the car to meet the correct conditions for active regeneration.