yes, cats were later; around 2010.
There is nothing as quiet as the stock muffler (around 89db IIRC) and since I like quiet, I have nothing bad to say about keeping the stocker......however it is very heavy and ugly.
My silencer post:
A subjective topic but to recap recent discussions;
I don't like loud but I've replaced the stock silencers on both KLR's for several reasons, namely; lighter weight (5 - 7 lbs), better tone, better looks. .....I wouldn't recommend it thinking there will be a noticeable increase in power, nor would I put much faith in manufacturer's that claim much in the way of HP increases (with no other changes).
After much research and some testing, I like the LeoVince X3 which is relatively quiet at 94db, doesn't require repacking (the only one that doesn't AFAIK
, except for the ridiculously expensive Staintune out of Australia), looks decent and has a spark arrestor and USFS compliance. Runner up would be the Lexx with the optional trail insert; also around 94db but it does require periodic repacking. I also like the FMF Q4 but it is a bit louder (though still trail compliant) at 96db (keep in mind that the increase in decibels isn't linear).
There are a great many aftermarket silencers on the market that are far too loud IMO and you'd do best to avoid them.