I have a 01 4runner SR5. I’m super confused with the inlet and outlet. I see some people saying 2.25 then 2.5. Idk what it is. Someone says the exhaust tip expands which makes it 2.5.

Trying to get an aftermarket exhaust tip.

 

Ya'd think somebody could show you how to use a tape measure

 

inlet is 2.25 outlet is 2.375. Can’t I round 2.375?

I’m not the best with math.

 

I could measure mine but it's not a stock exhaust any more. It's been replaced at least twice. Yours is probably not stock either. Might be a good idea to just measure yours.

I think you're talking about inner diameter and outer diameter? Not sure what you mean by rounding 2.375.