I'm almost 100% positive there is no "law" requiring a vehicle to have a CAT. Only that it must be below a maximum threshold of NOx pollutants. Now if a vehicle was equipped with a CAT as OEM equipment it is not allowed to be removed unless it has gone bad. Nor is it allowed to be sold without one regardless of if it was removed due to failure. That has nothing to due with state to state inspections though.
EDIT: The CATs on XJs are quite free flowing. Really there should be no reason to remove it unless it has became faulty or damaged. Even then I would seriously consider replacing it with at least a used one off a salvaged XJ.
^That.
EPA regs say it has to have "all OEM emissions equipment intact" - regardless of whether or not it's genuinely useful, or if it can be "tuned out" of an engine.
Further, a catalytic converter
or other spark arrestor tends to be requirement for vehicles registered "Off-Road Use Only" - if it's used
at all on a public roadway, adherence to EPA/local regs is
required.
A spark arrestor, of course, is to prevent glowy bits of carbon from blowing out the exhaust and starting wildfires - and a muffler (glasspack or baffle-style) is NOT considered a spark arrestor for our purposes here.
A proper cat is actually one of the more useful of the emissions devices - I'd run it, even for OHV tags. Not only will it keep the Leftist Greenie nitwits off our back, but it's also a safety device (as mentioned,) which can help keep you from getting caught in a fire. And, when you break it all down, there's no real reason to eliminate the thing anymore - through the late 1970s and early 1980s, we were still figuring them out - but these days? Random Technologies say that their bodies & matrices actually flow
better than a comparable section of straight pipe - so select a proper size exhaust, weld in a properly-sized cat, and you're good!
The problem with talking about emissions device removal as more than a theoretical subject is that it can bring the wrath of the feds down on you. You don't think that's bad? I am minded of a CB radio BBS some 20-odd years ago that got shut down - a discussion on "linear amplifiers" (to increase power output and transmission range) got running, and the people running the BBS got nicked for about $250K in fines (not because they did anything wrong, but because they didn't stop other people!)
The EPA, in many ways, can be even WORSE. Ergo, after I post this, I'm locking the thread. Please don't bring it up again - you have been warned.
