MOT question - Do I need a catalytic converter in my 95 300TDi for the MOT??

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freeagent:
yep, you are correct it is a particulate filter, not a cat, but the guy on here who's been MOTing them for 15 years insists its a cat, and I couldn't be bothered to argue... :rolleyes:

yellodisco:

--- Quote from: auf_wiedersehen_pet on January 02, 2008, 18:09:36 ---Do I need a catalytic converter in my 95 300TDi for the MOT??

The current cat is fine bit the wire mesh on the flexi joint has burst open and looks a real mess. I'm assuming it will fail because of this joint.

:lol:

--- End quote ---
Diesel's dont require cats for emissions tests on MOT, I am a MOT Tester mine is the same and it passed at a differant MOT!! station hope this helps

stageonesimmo:

--- Quote from: freeagent on January 18, 2008, 17:26:16 ---yep, you are correct it is a particulate filter, not a cat, but the guy on here who's been MOTing them for 15 years insists its a cat, and I couldn't be bothered to argue... :rolleyes:

--- End quote ---

--- Quote ---For compression ignition (i.e., Diesel) engines, the most commonly used catalytic converter is the diesel oxidation catalyst. The catalyst uses excess O2 (oxygen) in the exhaust gas stream to oxidize CO (Carbon Monoxide) to CO2 (Carbon Dioxide) and HC (hydrocarbons) to H2O (water) and CO2. These converters often reach 90% effectiveness, virtually eliminating diesel odor and helping to reduce visible particulates (soot), however they are incapable of reducing NOx as chemical reactions always occur in the simplest possible way, and the existing O2 in the exhaust gas stream would react first.

To reduce NOx on a compression ignition engine it is necessary to change the exhaust gas - two main technologies are used for this - selective catalytic reduction (SCR) and NOx (NOx) traps (or NOx Adsorbers).

Another issue for diesel engines is particulate (soot). This can be controlled by a soot trap or diesel particulate filter (DPF), as catalytic converters are unable to affect elemental carbon (however they will remove up to 90% of the soluble organic fraction). A clogging soot filter creates a lot of back pressure decreasing engine performance. However, once clogged, the filter goes through a regeneration cycle where diesel fuel is injected directly into the exhaust stream and the soot is burned off. After the soot has been burned off the regeneration cycle stops and injection of diesel fuel stops. This regeneration cycle should not affect performance of the engine.

All major diesel engine manufacturers in the USA (Ford, Caterpillar, Cummins, Volvo, MMC) starting January 1, 2007 are required to have a catalytic converter and a soot filter inline, as per new EPA legislation. http://www.epa.gov/otaq/highway-diesel/regs/2007-heavy-duty-highway.htm
--- End quote ---

Mmmm, I dont recall seeing the necessary system for this on my 300TDi. LIke I said waaaaay up there - in the days when the 300TDi was launched particle filter technology was in it's infancy and its complications like this that mean that the 300TDi IS fitted with a basic 'Oxidisation' Catalaytic Convertor and not a filter.

Oh and I'm not arguing, I just like to ensure that folk are given the right advice :wink:..............

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