Does that mean you "must eliminate the CAT before installing a tuner on a CAT equiped bike?
I would like to know the answer to this question also.
The entire purpose of having a catalytic converter is to convert (using a catalyst) the excess nasty CO (carbon monoxide) and HC (hydrocarbons) into something more friendly such as Co2 and H2o. During that process, a bunch of heat is generated.
When you richen up the mixture beyond the stoich point (perfect combustion ratio) you create an abundance of CO & HC. The Cat now goes into a flooded or a saturated condition. It wouldn't be too bad if you were stoich most of the time,, like during cruise. But eliminate the O2 sensors or go wide band and chances are your no longer stoich at ANY time. The Cat now is working 24X7 trying to get rid of the constant excessive stream of CO & HC. Granted a miss-fire is a ton of unburned fuel, but I have seen Cats glow caused from a miss-fire on a cage. (1 cylinder out of 6 dumping raw fuel)
Based on what the warranty is on a Cat from the Moco (only 18,000 miles), that alone tells me the factory Cat is having a hard time with a STOCK bike with a stock A/F ratio,,,let alone a ratio that has been modified.
We are not going outside the air ratio window by just 1/4 point or so. In most cases I would bet we are pushing it a good Full point during cruise and 2 points during WOT.
Bounce some of these numbers around in your head and tell me what you think about how long a cat would last running 13.5 at cruise or 13.2 at idle.
Just a wild guess because I have no facts to back it up. I bet a new cat would not last 10 thousand miles on MY bike. Probably even less than that.
(I am open loop 100% of the time)
