Dual Exhaust on 1996 Grand Marquis - X-pipe vs H-pipe
 

I have a '96 Grand Marquis and am looking to upgrade to a dual exhaust system. I have barely squeaked by state inspection for the past two years because of a bad catalytic converter on the right side, and bad O2 sensors. I love this car, and have had it for 9 years, and want to keep it running and make some improvements. Since I have a bad cat anyways, I would like to put in direct-fit high flow cats (I was thinking Eastern Cat. #30316 & 30315), and a true dual exhaust system.

I have never done any exhaust work, so pardon my ignorance, but I want to figure out what will be best for me without spending a fortune on a car with 258,00 miles on it (I have taken great care of it, and had some major transmission work done in '07). I would love to get some advice on how to go about dual exhaust, and have a few questions for fellow Mercury enthusiasts-

1) X-pipe or H-pipe? What will provide a better flow on this vehicle? I was thinking about getting a Magnaflow Tru-X pipe kit (2.5 in). Good/bad idea?

2) Mufflers - I was thinking about Magnaflow performance mufflers (#11216) with 2.5 in inlet&outlet. Good/bad idea? I want to get some good sound, but not to the point of being too obnoxious. Some of the flowmaster setups on youtube are a little too much noise for me, but I do want to get some decent tones.

3) Resonator or Resonator Eliminator? If I get a performance muffler, I don't want to stifle it too much.

4) How is the clearance of the vehicle affected with dual exhaust? I live in the mountains, and have to deal with some challenging roads. Also, I have a trailer hitch bolted to the frame of my car, and use it pretty often. Could this be a problem?

5) Anyone with a custom dual exhaust setup on a Grand Marquis or Crown Vic have any suggestions for me? or do you think the parts I mentioned sound good and will work well?

My uncle has offered to help me install everything if I get the parts, but he lives in Maryland, and I don't want to order any wrong parts (or be missing parts) if I make the long drive. I have a recommendation for a good exhaust guy nearby, but I want to know what I want when I go in, and not be taken for a ride. My goal is to keep the whole project under $1000. Any tips would be greatly appreciated. Thanks for reading,

Best, Nick.

Did the dual conversion on a 2001 several months ago. Meineke muffler shop did the conversion for me. We simply followed the Crown Vic/Grand Marquis police package dual exhaust (H-pipe) setup. I used inexpensive Turbo mufflers without resonators. The sound is simply a deep rumble. The whole job, including taxes, was $440. Meineke provided everything including, of course, bending the pipes.

My 95 GM has the factory dual CATs, 2" pipe into a X pipe into Flowmaster 40's. It sounds insanely amazing. The 40's are a nice low tone until you punch it and WOW. It just rocks....hardcore rocks

H pipe provide better hp and torque than stock... the X pipe allows even better hp but less torque than the H pipe... clearance will be fine since there are mirror image mount holes under the car since police and other models had dual exhaust...

Can you reuse your current muffler and tailpipe in a dual exhaust conversion? Would it make any difference if the two mufflers were not the same?

My experience
 

Earlier this month a muffler shop converted my 2008 LS to a y-pipe with stock mufflers for about $360, reusing my factory muffler and tailpipe. The increase in acceleration is very slight, and it only averages about one to two more miles per gallon. (It sounds exactly the same.) Nevertheless, with current gas prices this should pay for itself over the next several years. I have never kept a car for less than 115,000 miles or seven years. Plus it looks cooler now and my impact on the environment has been slightly reduced.

'95-'97 Grand Marquis Dual Exhaust
 

What You'll Need For The '95-'97 Grand Marquis Dual Exhaust.

Walker H-Pipe -- (Part #40383) NOTE: When installing H-Pipe, use stainless steel bolts, nuts, and lock washers.
MagnaFlow 2" Glasspacks -- (Part#18134)
Walker Tailpipes -- (Part #46761 Right -passengers side).
(Part #46789 Left - driver's side)
Stainless Steel, slant-cut tips. (Superior Part# 28-6201).
When building your dual exhaust system, DO NOT go bigger than 2" outside diameter - Torque and Power will DECREASE !!
I got the exhaust system parts from Amazon.com, clamped it up to check for fit, and had the system welded up at "MufflerMasters", Avondale, AZ.

1.- Home-Made Cold Air Intake with K&N Air Filter - (Part #33-2272). NOTE: The "flat" filter has more surface area
than the conical filters used on those aftermarket CAIs - AND they're MUCH easier to clean and oil properly !!
2.- Mallory Adjustable Fuel Pressure Regulator @ 35 psi, (hot idle) with all hoses connected and accessories turned OFF.
3.- Walker-MagnaFlow dual exhaust.
4.- Stainless steel exhaust tips.
5.- B&M Shift Improver Kit - (Part #40264)
The whole performance package was less than $300, including the CAI, Dual Exhaust, and the B&M Shift Kit

Results: Quarter Mile @ 16.2 -- 88 mph -- 1100' elevation, 94 F outside temp.

Conversion to Duals
 

Re-using the stock muffler and tailpipe on a dual exhaust conversion is NOT a good idea -- and YES, it WILL make a difference if the mufflers are not the same !!
The whole purpose of a dual exhaust conversion is to have a BALANCED, high-flow system.
Both mufflers should be EXACTLY the same part number for best results.

I used:
Walker H-Pipe; MagnaFlow 2" Glasspacks; Walker Tailpipes.