Need 2004 GM dual exhaust
 

Looking for a new exhaust for my 2004 GM LS. Car has single and want duals. Can i get rid of cats and get just an old school dual setuo?

2004-2011 Grand Marquis Dual Exhaust
 

Hello, C.Rob, and welcome to the Mercury Forums --
Regarding FOMOCO Catalytic Converters -- DO NOT DELETE these cats !! The factory cats will flow more air than a straight pipe -- they are NOT an exhaust-gas restriction. NO power or mileage gains come from FOMOCO cat removal -- just A LOT of NOISE !!.
Going from a single exhaust to duals, however yields 20-24 HP at the wheels, with no sacrifice in fuel mileage..
To go from a single pipe to duals on your Grand Marquis, you'll need:
(1) Walker H-Pipe - #50328
(2) H-Pipe Flange Gaskets
(4) Stainless-steel Flange bolts, nuts, & lock washers.
(2) MagnaFlow # 18134 -- 2" x 21" (body) Mufflers -- max flow, no louvers, no baffles, no droning.
(1) Walker Left-Side Tailpipe
I got all the parts from Amazon.com (delivered) and installed all the pieces, then had it all welded up at
MufflerMasters of Avondale, AZ.
TOTAL COST = $240
Above info is for The 95 MERC -- Check the part numbers for YOUR year of manufacture before ordering.
https://cimg6.ibsrv.net/gimg/www.mer...f89c69f476.jpg
Walker H-Pipe; MagnaFlow 2" Glasspacks; Walker Tailpipes.