American RV Motorhome Servicing Observations

When we carry out a service at LAS Motorhomes we complete a number of checks.  One of these checks is to test the emissions.  The emissions can tell you quite a lot, for instance, if the engine is running rich or lean, and also if the engine has a misfire.


A new catalytic converter

The problem that we have started to come across is a high reading on our gas analyser of CO2.  This is being caused by the failure of the exhaust catalytic converter.  A catalytic converter will reduce the pollutants that the engine produces by up to 40%.  It works by using two different types of catalyst, a reduction catalyst and an oxidation catalyst, both of the catalysts consist of a ceramic structure coated metal catalyst usually platinum,   rhodium and or palladium.  The problem that occurs is that the ceramic structure inside the metal casing brakes up into small pieces and they are forced into the exhaust silencer, leaving the catalytic converter an empty shell.  This, in turn, increases the CO2 reading above the MOT requirement leaving only one option that is to replace the catalytic converter and exhaust box.


Honeycomb construction of the catalytic converter


A new silencer


The view inside the new silencer