Catalytic converters
Failed your NCT on emissions? What to do next
Why a vehicle fails the NCT emissions test, what the CO, HC, lambda and smoke readings mean, and how to fix the cause and pass the re-test within…
DPFs and GPFs
Practical articles on catalytic converters, DPFs and GPFs, emissions tests and choosing the right part for your vehicle.
Catalytic converters
Check anti-pollution system: what it means and what to do
Check anti-pollution system or anti-pollution fault? What it means on Renault, Dacia, Peugeot and Citroën, what to do, and when the cat or DPF is to blame.
DPFs and GPFs
DPF fault codes P2463, P2002, P242F, P2453 explained
What the DPF fault codes P2463, P2002, P242F and P2453 mean, what a garage should check first, and when the filter itself needs replacing.
DPFs and GPFs
What is a GPF? The petrol DPF explained
A GPF (petrol particulate filter) is the petrol version of a DPF: which petrol vehicles have one, the warning lights, and whether it can be removed.
Looking for the basics? Our Help & Advice guides cover how catalytic converters and DPFs work, fitting, the law and warranty.