Different terms found while trying to purchase and service catalytic converters. High flow, Heavy metal - heavy loaded, OBD-II, OBD-I, metal core, ceramic core, etc. What do these terms mean?
After searching I was able to find little information from one website, about the different terminology used while trying to find a converter. Most detailed information seems to be spotty a best, coming from users of different forums.
Here are a couple of links, with some information from one source about catalytic converters. (Since I don't know much about catalytic converters I am unable to condone or vouch for the accuracy of this or any other information coming from elsewhere.)
http://www.ebay.com/gds/What-you-need-to-know-about-choosing-a-converter-/10000000002569538/g.html
http://www.bearriverconverters.com/index.aspx
High Flow Converter
This term has been misused and abused. Standard converters use a ceramic catalyst with cell densities of 400 cpi or higher. True high flow converter will use ceramic or metal substrates with 300 cpi or lower.
Heavy Metal or Heavy Load
This term is somewhat misleading. It indicates that the converter has higher loading than many other 49 state products, but does not tell you how much loading or of what type. Typically these converter have increased cerium or zirconia contents, which can sometime help prevent catalyst related codes, but this is mostly a marketing keyword.
OBD-II or Designed for OBD-II
This means the converter has increased cerium or zirconia content. This is required for proper OBD-II operation, however, it is mostly a marketing tool used to convince the customer that the product will work on their car. These converters are ok for some applications, but lack the proper precious metal content and coating methods to resolve the more difficult applications.
ECO-II
Converter bearing this tag contain elevated precious metal and cerium or zirconia. The current generation ECO-II catalysts have increased rhodium and palladium coatings for proper function on most OBD-II equipped vehicles. Unlike the vague terms used by other companies, this term tells you what kind of catalyst you are getting. Converter containing this catalyst will bear a green sticker and have a green dot on the substrate.
ECO-III
This designation is similar to ECO-II, but has a higher rhodium content for increased efficiency. This catalyst is used for difficult applications when other products may not work. This catalyst is most often used on 2003 and newer applications, especially those that have known histories of problems. Converters containing this type of catalyst will bear an orange sticker and will have an orange dot on the substrate.
ECO-GM
This is a special catalyst designed for popular GM application. Many GM cars have special requirements that make most aftermarket converters unsuitable. These converters feature advanced washcoats that closely mimic the original equipment loading. These converters are designed specifically for the 2.2L, 3.1L, 3.4L and 3.8L GM engines. Converters bearing this designation should not be used on other applications. Converters containing this type of catalyst will have a purple sticker and will have a purple dot on the substrate.
