Removing a catalytic converter (or multiple) from any exhaust system will not "use up more fuel". I have owned many Mustangs w/o ever having any fuel issues on those that did not have any cats.
The O2 sensor on most if not all vehicles is BEFORE the cat, so if a cat is removed, the O2 readings will not be affected. Some newer vehicles have 4 O2's - 2 before the cat(s) and 2 after, on those vehicles there would be some concern about engine data exchange to the DME for the O2's AFTER the cats which could in turn cause the computer to go into an open loop phase as it's trying to compensate for the change or data exchange from those O2's that are no longer "seeing" the cat(s)...
Removing a cat or smog pump will not make a vehicle unroadworthy either - you can still drive the car around, it will still operate and function the same, however it will be LOUDER
. Some vehicles sound good w/ cats removed (ie: V8's w/ dual exhaust) while some sound horrible (ie: some 4 cyl's and 6 cyl's) - it really depends on how the rest of the exhaust system is designed too (ie: diameter of pipes, type of muffler(s) or no muffler(s), iron manifold(s) vs performance SS manifold(s) and if a single or dual exhaust).
Removing a cat (or multiple) can be a performance gain (less back pressure), however, in some instances some vehicles, depending on engine displacement and if naturally aspirated function better on the back pressure of cats inline w/ the exhaust.
In some States here in the US, removing a cat (or multiple) can be illegal, especially if that State has emissions inspections. Some US States or areas within said States are emissions exempt, so those folks can remove such parts without getting into trouble. If you are one who wants to remove the cat, just be smart about it...
Topic: Deleting the Cat. converter? (Read 2529 times)