My 999 has a standard exhaust system including CAT pipe but the silencer has been opened gutted and closed back up. Unfortunately I don't know by who. It's running standard ECU chip, sounds great runs ok if not a bit rich. Question is will do any lasting damage? The shop I bought from says not but I'm not so sure, should I fit standard silencer, cheap on eBay or fit power commander and remap if so what would be the benefits or gains if any Cheers
If you do anything - take it to Chris Steedman of CJS Racing and get your ECU remapped to suit that cored-out exhaust: that's far and away the best use of any money you might be thinking of spending on it... No it won't do any damage as it is but the best way to get it running as good as possible is to get the ECU remapped. For max performance benefit you might want to find a cat-less mid pipe on eBay first and then let Chris work his magic.
You only mention that the silencer has been gutted, but what about the CAT pipe? This since the CAT for the vertical cylinder is in the silencer, but the CAT for the horizontal one is in the pipe. Did you already check if that one is removed? You would typically see welding where it has been opened to gut it out.
