everyone on here says stock exhaust is 2.25. i figured i would just keep the stock piping, add a muffler....2.5 isn't that much more. well i went under my car, and noticed its pretty small. the pipe that connects to the muffler is in fact 1 7/8" ID, i guess ill be replacing the piping, hopefully they can custom bend it over the suspension, it looks tricky.


just a FYI

(2001 3400 GLS btw)

it's possible, mine is 2.5" although it requires a little "adjusting" around the rear swaybar with a hammer.

After you put away that 12 pk of busch I guess so. :lol:

j/k.

Actually will this effect the O2's ?

Haha, not me on the busch, that's my dad's. The O2s are still stock as is the front pipe and i even left the factory resonator (it's a little trimmed from that pic). The car had just over 1000 miles when it was installed, i'd rather not modify any emissions stuff yet!

IS the stock cat 2.25 inches? :unsure:

the downpipe is 2" ID, maybe 2 1/8". the cat outlet is 1 7/8"....so i guess its a mix

yea, 1 7/8th I said that a long time ago, but I thought it was only for the 2.4. Now that I think about it, at the factory they only had 1 bin of exhausts. heh

poop so am I going to throw a code with my headers and cat kit?

IF so, is it only the downstream O2? or will both become bad :unsure:

i had a 3" cat, stock o2, no codes.

If the cat is doing its job, you won't thorw any codes. the first O2 sensor before the cat measures the air/fuel ratio and sends it to the computer to run the fuel injectors. the second one after the cat also measures the a/f ratio, but only to tell the computer if the cat is doing its job cleaning the exhaust. if you have a bad cat, only then will you throw a code.

^cool thanks :thumbsup:

I measured the circumference on my 2.4L's exhaust then used the circle circumference formula [diameter = circumference/(pi)] to figure out the diameter. It's less than 2 inches for sure.

like it was said

its 1 7/8"