The gravana tuning site says the pacesetter ceramic coated 4-1 header (for my 2.4) which costs $209 is 1.5 inches inside... Is that accurate? How do people say they have that and a 2.25 exhaust? Does the interior diameter not matter since there are 4 pipes going to the 2.25 cat. converter?
they were probably talking about each runner, not the main pipes...
i really doubt anyone besides maybe geo metros or smaller that have a 1.5 inch collector.
in reference to aftermarket headers.
primary tube is 1 1/2" the extension pipes are from the header to cat is 2 1/4"
