What does homologated mean on a catalytic converter or DPF?

Homologated means type approved. A homologated catalytic converter or DPF is a replacement part that has been tested and approved by a government approval authority for a specific list of vehicles, and it carries a permanent approval mark to show it^1,2. It’s the word in our product names, such as “Homologated Petrol Cat”, and what the H stands for in a BM Catalysts part number such as BM91752H³. Here’s what it means, when the law requires it in Ireland, and how to check a part.

What “homologated” means

EU type approval is the procedure by which an approval authority certifies that a type of vehicle, system, component or separate technical unit meets the relevant technical requirements¹. A technical service, designated by the approval authority, carries out the tests¹, and the authority that granted the approval must check that the manufacturer goes on producing parts that conform to the approved type, which is called conformity of production¹. In Ireland the approval authority is the National Standards Authority of Ireland (NSAI)⁴.

UN Regulation 103 sets out how replacement catalytic converters are approved. The Euro 5 and Euro 6 rules use its tests, with some changes, for every replacement “pollution control device”, the law’s term for the parts that control and limit a vehicle’s emissions, and they name catalytic converters and particulate filters as pollution control devices, so DPFs and GPFs are covered too². The replacement is tested on a vehicle in place of the original part and checked for emissions, durability and compatibility with the vehicle’s on-board diagnostics (OBD), the system that monitors the emission controls and stores fault codes².

An approval covers specific vehicles. Under the Euro 5 and Euro 6 rules a homologated part must come with the list of vehicles, with their years of manufacture, that it is approved for². That is why a homologated part is listed against particular models and years. BM Catalysts, who make every part we sell, say their homologated range is tested in accordance with UN Regulation 103⁵.

When the law requires a homologated part

The rule is in Article 11 of the EU’s Euro 5 and Euro 6 Regulation, which applies directly in Ireland⁶:

Part	Vehicle	Must it be type approved?
Catalytic converter, DPF or GPF	Approved to Euro 5 or Euro 6	Yes6
Catalytic converter	Approved to an earlier standard, once approval rules for replacement catalytic converters applied (they date from 19987)	Yes6
Catalytic converter	Approved before those rules existed	No: exempt6
DPF	Euro 4 or earlier	No: the EU approval rules for replacement particulate filters cover vehicles approved to Euro 5 and Euro 62,6

Euro 5 applies to new cars and the smallest vans registered from 1 January 2011, although new models had to meet it from 1 September 2009⁶. A vehicle’s type approval comes before its first registration, often by years, so for an older vehicle the registration date alone may not settle it: if you’re not sure, ask us before you order. Our Euro emissions standards guide explains the levels.

The rules are enforced against businesses. In Ireland it is an offence for a business to make available on the market a component that is subject to approval without that approval, with fines of up to €100,000 on conviction on indictment⁴. Our guide to type approval and the law has the detail.

Homologated, original, non-homologated and universal

• Original replacement: the vehicle manufacturer’s own part, marked with the manufacturer’s name or trade mark and part number and listed for the vehicles it fits².
• Homologated (type approved): an aftermarket part approved as a replacement for the vehicles on its approval².
• Non-homologated: not approved, so it can be fitted only where the law does not require approval, such as a DPF for a Euro 4 or earlier vehicle^2,6.
• Universal: a catalytic converter made to be adapted to many exhausts. BM Catalysts, for example, make their universal cats without necks so that pipe stubs of the required bore can be welded in⁸. Where the law requires an approved part, one can be fitted only if its approval covers your vehicle⁶.

Does the NCT check for a homologated part?

Not directly. The inspector checks that the emission control system fitted by the manufacturer is present, complete, properly connected and not bypassed, and fails a vehicle if it is absent, modified (on a petrol vehicle), incomplete or obviously defective. A catalytic converter, DPF or EGR valve that was fitted when the vehicle was made but is now missing is a major fault. The emissions are measured too⁹. None of these checks covers the approval mark.

So a pass does not prove a part is approved, and selling a non-approved part where the law requires an approved one is still an offence for the business that sells it⁴.

What homologated means when you buy one

• Fit and Euro level. The approval ties the part to particular vehicles and their Euro level. BM Catalysts point out that parts for different vehicles and Euro levels can share the same housing and pipework yet differ inside, so a part that can be made to fit is not necessarily approved for your vehicle¹⁰.
• Emissions. A homologated part has been tested on a vehicle in place of the original², but it cannot make up for an engine fault: the cause of the old part’s failure has to be fixed first, or the new one can be damaged too¹¹. See failed your NCT on emissions?
• Warranty. Our catalytic converters and DPFs carry a 2-year warranty, 3 years on Premium silicon-carbide DPFs, covering manufacturing defects. BM Catalysts exclude, for example, impact damage, oil fouling and exhaust paste used in front of a catalytic converter¹¹. See how to claim.

How to tell if a part is homologated

1. Look for the approval mark. An approved replacement catalytic converter or DPF for a Euro 5 or Euro 6 vehicle bears an EU approval mark: a lower-case “e” in a rectangle followed by the distinguishing number of the member state that granted the approval, with the approval number next to it². The number for Ireland is 24¹². Parts approved under the UN scheme carry a capital “E” mark instead¹³. Wherever possible, the mark should be visible once the part is fitted².
2. Check the vehicle list. The part must be clearly marked with its manufacturer’s name or trade mark and come with the list of vehicles it is approved for. If your vehicle is not on it, the part is not approved for it².
3. Ask for the certificate. If in doubt, ask the seller or the manufacturer for a copy of the type-approval certificate.

In our range, homologated parts have an H at the end of the part number (HP on Premium DPFs) and show Type Approved on the product page, which lists the vehicles, years and Euro level each part is catalogued for (see BM Catalysts part numbers explained). Each BM unit also has a serial number of six letters beginning with C or D, usually pin-stamped on its body: note it before fitting, as it is needed for any warranty query¹¹.

Approvals across the EU

An approval does not have to come from Ireland. EU member states may not prohibit, restrict or impede the sale of components that comply with the EU type-approval rules¹, so a part approved by the authority of any member state can be sold here. The EU is also a party to the UN agreement behind UN approvals¹⁴, and the Euro 5 and Euro 6 rules build on UN Regulation 103 for replacement parts².

Finding a homologated part for your vehicle

Every part we sell is manufactured by BM Catalysts. Every combined catalytic converter and DPF, catalytic converter and GPF and SCR and DPF unit in our range is type approved, and so is every catalytic converter and DPF we list for a Euro 5 or Euro 6 vehicle. Among our catalytic converters and DPFs, the parts without an H are catalytic converters listed for Euro 1 and Euro 2 vehicles and for some imported vehicles, and DPFs for Euro 3 and Euro 4 diesels. Most parts come with a fitting kit included, all carry at least a 2-year warranty and are backed by our fitment guarantee, and we deliver to the Republic of Ireland for €30.99 per order, usually within 2 to 3 working days of dispatch. Enter your vehicle below to see the parts catalogued for it, or choose it from the vehicle list.