wrestler4life902

well i searched but i didnt find anything but im kinda new to this so mayber didnt search right. but i was just wondering the stock exhaust size on my 1999 4runner. if anyone knows this it would be great help thanks.

algranger

i dont have a runner but my guess would be 2" why dont you go measure it?

wrestler4life902

well i did measure it and it was 2.5'' but the end of my pipe looks like it gets bigger at the end so im not sure...

camo31_10.50

well you could get a little bit more dirty...and crawl under the truck..measure it in a few different places just to be sure...i think the size is 2 1/8...but most people use the 2 1/4 when getting a new exhaust...nice snug fit over the 2 1/8

Elton

its some where around 2.25'' which is more than enough for a stock motor now if you put a s/c on bump it up to 2-1/2''

312necro213

its stock 2.5" all the way back from the motor on my 2001. Ill bet its the same.

wrestler4life902

yea i got down underneth it and i measured 2.5'' so i guess that must be right

JC_ez

The stock 4Runner pipe size is actually metric, but it very closely matches 2.375" outer diameter and 2.25" inner diameter. Since pipe diameter is usually measured as the outer diameter, i suggest not going with a 2.25" pipe because it will actually be smaller than your stock pipes. Also, the all 3rd gen 4Runners have a flared section of the tailpipe right at the tip where the diameter gets slightly larger for the last 4.5" or so. I've done extensive measuring at several points from the muffler outlet to the tailpipe inlet and outlet.

wrestler4life902

yea thats what had me confused was the flare on the tailpipe. yea it wasnt exactly 2.5 but seemed close enough thanks for the help