How to Buy a Catalytic Convertor for a Honda Car

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How to Buy a Catalytic Convertor for a Honda Car

A catalytic convertor can be an expensive part to purchase, even for a vehicle that delivers economy. Fortunately, catalytic convertor buyers have several options to choose from, that can help them find parts at prices to fit their budgets. Buyers can elect to purchase a catalytic convertor used or new from an aftermarket vendor or select an original equipment manufacturer (OEM) part from the dealer.

Understanding the advantages and disadvantages of each type of part can help the buyer make an informed purchase decision and choose the type of part that is suited for the needs. It is also important to know that the part being purchased fits the buyer’s vehicle properly and performs as intended. Honda catalytic convertors can be purchased from Honda dealers, auto parts stores and specialty exhaust vendors. Used Honda convertors can be found at salvage yards and occasionally at automotive swap meets. Sellers on eBay offer both new and used Honda catalytic convertors for sale through the eBay Motors online marketplace.

The Importance of a Catalytic Convertor

Catalytic convertors are used on petrol vehicles to reduce exhaust emissions. The catalytic convertor is located in the exhaust system,, between the exhaust manifold that attaches to the engine and the tail pipe that expels exhaust gases away from the vehicle. The exact location of the convertor varies with the design of the vehicle but it is always positioned between the engine and the muffler..

On some Honda models, the convertor is attached as a part of the exhaust manifold; other models place it in the more conventional position under the floor of the vehicle. Inside the convertor, a system of ceramic honeycombs are treated with chemicals that react with the exhaust gas produced by the internal combustion engine. The chemicals are the catalyst that produces the molecular reaction that converts harmful gasses like carbon monoxide into carbon dioxide and water. Not all molecules are converted, but the total amount of emissions is cut significantly

Why Catalytic Convertors Fail

Generally, convertors fail due to the engine running rich or burning oil from failing seals or rings. The vehicle’s oxygen sensor monitors the amount of unburned petrol that leaves the engine and travels into the exhaust system. When the engine is running rich, the oxygen sensor sends a signal to the engine’s control unit that is supposed to clean out the mixture. If the oxygen sensor fails, the control unit does not get the information to properly adjust the mixture. Oil that passes the piston rings or valve seals does not burn properly in the combustion chamber, and the residue is also forced out into the exhaust.

Oil or excessive amounts of unburned petrol attach themselves to the catalyst and clog the convertor. When clogged, the convertor overheats as it attempts to burn off the excess hydrocarbons. Overheating can cause the catalyst to crack and break. If the hydrocarbons cannot be burned off, the convertor gets plugged and ceases to function. A restricted exhaust prevents the engine from running properly; the vehicle then exhibits a severe lack of power on acceleration. One sure sign of a failed convertor is a reduction of exhaust gases emitting from the tail pipe.

Options for Buying a Catalytic Convertor for a Honda Car

Buyers have the option of selecting from three types of parts when purchasing a catalytic convertor for a Honda. Prices vary between the different types and so can the quality of the product. How the part is warranted may also be an important factor in the buying decision.

Buying a Used Catalytic Convertor

Used catalytic convertors are probably the least expensive option available to convertor buyers. However, there is no guarantee to the quality of the product. If the convertor was removed from a relatively low mileage vehicle, it may have many years of service still available. Convertors are built to fit specific models and are not interchangeable. Some parts are used over several model years so the buyer needs to make sure the part matches the specifications of the vehicle for which it is purchased. Due to potential conflicts with the European Community Type Approval requirements, some shops may not install a used catalytic convertor..

Aftermarket Catalytic Convertors

Aftermarket is a designation of automotive parts that signifies that the vehicle manufacturer did not produce the part. Aftermarket parts are a copy of the Original Equipment Manufacturer, or OEM, part that are produced without the benefit of the original design specifications. The lack of engineering specifications can produce issues with some parts, especially concerning proper fit and finish. With regard to an aftermarket catalytic convertor, the fit specs are somewhat flexible as there is generally plenty of flexibility in the movement of exhaust parts to render a minor fraction of difference to be accommodated easily. Fit and finish are more significant with body parts and light lenses. Aftermarket catalytic convertors are generally much less expensive than OEM parts and somewhat more expensive than used convertors.

The Function and Legality of Aftermarket Catalytic Convertors

In terms of function, catalyst designs have been on the market long enough for the technology to become well known. Aftermarket convertors perform very similarly to the original OEM convertor that came with the vehicle when it was new. As of August 2009, it is illegal to install a non-approved catalytic convertor on any vehicle in the United Kingdom, or fines can be assessed. The law applies to all vehicles registered on or after 1st March 2001; these vehicles include Y registrations and forward. Buyers should be certain to purchase an EC Type Approved catalytic convertor if the vehicle falls under the regulation. There are many non-EC Type Approved convertors on the market, so be sure to ask about proper certification of the part before making a buying decision.

OEM Catalytic Convertors

The OEM designation means the catalytic convertor was produced at the request of and to the specifications of the vehicles manufacturer for installation during the vehicle build process. A common source of OEM parts is the parts department of an authorised new car dealer that represents the brand. Honda dealers offer original equipment catalytic convertors for sale and installation. OEM parts are usually an expensive option for Honda catalytic convertor buyers, although they are backed by Honda against defects. All OEM catalytic convertors are EC Type Approved.

The following chart provides a quick comparison of used, aftermarket, and OEM catalytic convertors. The advantages and disadvantages of each type are discussed, along with comparative price and warranty information.


OEM Part

Aftermarket Part

Used Part


Exact fit and performance, readily available

Less expensive than OEM, good warranty, readily available, good fit, and performance

Least expensive option, exact fit when VIN matches part


Expensive option

Fit may require minor adjustments

Potential for quality and performance issues






Buyers can use the vehicle identification number, or VIN, to cross reference the fit of a used part. This helps them ensure they get the right parts for Honda vehicles.

Buying Honda Catalytic Convertors on eBay

Sellers on eBay have used, aftermarket, and OEM catalytic convertors for sale at competitive prices. Using the search parts and accessories feature of eBay Motors,, buyers can be sure to find the proper fitting catalytic convertor for a make and model of Honda. Simply select 'Honda' from the drop down menu under vehicle make and select the Honda model you own. Then enter a search term such as "catalytic convertor&", in the keyword bar. The search returns applicable parts for the model of Honda you own. Select the part for the proper model year of Honda and decide which type of convertor suits your budget and needs.

Buyers can purchase with confidence by reviewing seller feedback ratings to see how a seller has been rated by previous customers. If you have questions about the product, you can contact the seller using the 'Ask a question' link on the listing page. Complete your transaction by using a method of payment, and rest assured about the safe and secure online transfer of money.


Due to the high salvage value of catalytic convertors, theft has become a serious concern for vehicle owners. A thief with the proper tools can remove a catalytic convertor from a vehicle within a matter of minutes. Theft has become one of the big reasons for the replacement of catalytic convertors.

Regardless of the reason, before a Honda owner purchases a catalytic convertor, an understanding of the options available on the market can help the buyer select the part suited for the needs. Being aware of the common causes of catalytic convertor failures can help vehicle owners monitor the performance of the petrol engine and seek repairs when engine monitoring systems indicate a problem that could affect the convertor. Selecting a convertor that meets certification requirements can prevent vehicle owners from running afoul with the law. Recognising the price differences between convertor types can help buyers find part that fit both their budget and their Honda vehicles. Thanks to the many options available on eBay, this is not a difficult task.

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