Larger Exhaust on a D24 NA?

[v8volvo]

Interesting. That does add up, I have a few friends with Priuses in CA who have been hit for their catalysts.

I don't think there would be any issue driving my cat-deleted LR into a more restrictive state like WA/OR/CA. AFAIK there are no programs at least currently where they can conduct a roadside emission equipment inspection of a private personal vehicle owned out of state. Though I believe such programs do exist or are coming soon for commercial vehicles, at least in CA, even if they're registered elsewhere.

But if I wanted to register my non-compliant LR in WA for example, in a county with visual and/or emissions inspections, then I am sure I would have a problem. I think even a check engine light is enough to fail.

Makes sense on the expansion chamber concept. Combined with some baffles or packing for even better effect? Anything to take the rapping-type pulses out... Though as you say the turbo does a lot of that. Even a straight piped D24T is a little loud but not completely offensive at least IMHO, since the turbo kind of seems to round off and soften the sound. Whereas an unmuffled NA engine seems to have a lot more rasp/blat/snarl. Might not be that much louder really in terms of db, but the quality of the sound feels harder on the ears.