Exhaust differences Marquis-PI?

Are there any differences in the exhaust system (from the cats back) between a 2005 Grand Marquis and a Police interceptor?
I have a GM that came from the factory with a single exhaust, the pipes join behind the back cats.
I want dual, would like the stock dual pipe for the GM, but I can get the exhaust from the cats back from a used Police. Will it bolt up? Or must I have a custom exhaust installed?
Thanks.
Chris

You need the H-pipe, the drivers side muffler/tailpipe from the Police Interceptor, and the hangers for the drivers side(you may be able to still get these from Ford but they seem to be running out of spare parts already).
You need the system from an '03 or newer.

Go check out Walker muffler website for all the part numbers needed (cheaper than Ford). Or go to a local junk yard for the parts off a police interceptor.

The other choice is to have a muffler shop make you a new system with the h-pipe crossover from the cats on back. If you go this route, get the pipes about 1/4 inch larger diameter.

You may also want to go checkout what others have done at www.crownvic.net.

Remember the emissions crap. You will need O2 sensors and all that crap. May have to reprogram the computer, too.

I'm having problems with my 03 CVPI andit is all from sensors on the passenger side catalytic converter.

Thanks for the replies.
I may not have made my question clear.

I have a complete, factory stock, single muffler exhaust.
This has the same 4 cats, O2,sensors, etc. as any other 2005 GM. Or CV, as my passenger cat is from a 2003 CV. I swapped them, exactly the same part, as you would expect.

However, I want to replace everything AFTER the Cats, thus maintaining my California Legal emissions status.
I can get a complete exhaust, not the cats but back to the tail, from a 2003-6 (unknown exact year) Police Interceptor.

What I'm trying to find out is if it is a bolt on.
The original muffler is huge, and is behind the axle. That will have to go, so I will have to replace with the factory H-pipe and factory PI mufflers. I assume that there will be no resonators as the PI doesn't seem to have them.

So I was asking if anyone knows if it is a straight swap, the PI Victoria H-pipe, intermediate pipe, two mufflers, and tail pipes, or if the GM with single exhaust has some modification that stops the PI stuff from going under there.

If the parts were close, I could compare them. They are 90 minutes drive away, and I would have to pick them up with my Minivan as the pipes, mufflers, etc. would not fit in the GM trunk.

So, anyone ever do this? Put a PI exhaust, complete, on a GM? Post 2003?
Thanks.

Quote:

Remember the emissions crap. You will need O2 sensors and all that crap. May have to reprogram the computer, too. I'm having problems with my 03 CVPI andit is all from sensors on the passenger side catalytic converter.

What part exactly do you need?
I have a passenger cat pipe (two O2 sensors, two cats, in perfect working condition.) 74K miles, just passed smog a week ago. I replaced it because I had a spare, and the original had a ding in the shield.

I'm in California and here you can only use factory gear, or the insanely high priced 'California only' stuff.
Same converters, just with big government numbers on the side.
This state is insane.

Quote:

Quote: You need the H-pipe, the drivers side muffler/tailpipe from the Police Interceptor, and the hangers for the drivers side(you may be able to still get these from Ford but they seem to be running out of spare parts already). You need the system from an '03 or newer.

I take that to mean that they are interchangeable?
The PI is the same pipe diameter, length, and will fit under the single pipe GM?
I will get the hangers with the system when I pick them up, so that shouldn't be a problem.

I've worked on many vehicles where the parts didn't interchange from variants, so I have been concerned.
A change in gas tank mount, or rear bumper cover can make a big difference on many vehicles.


Since it is California, paying a shop to just fabricate a dual exhaust would cost two or three times as much as it would elsewhere, so I'm hoping to put this used PI dual system under there for no more than a new exhaust would cost in other states.

Thanks for the help.

I'm posting back to answer my own question, for anyone else with the same situation.
The factory single on the 03-06 (don't know about others) exhaust is the same part exactly as the factory dual exhaust right hand. That is from the muffler to the tailpipe.
The factory just puts an H pipe, in place of the Y pipe, then hangs the drivers exhaust from the H. The three 10mm head, 8 mm self taping bolts already have holes drilled for them.
I put a 06 police interceptor dual exhaust under my 05 GM in about 3 hours.
The exhaust, with about 3k miles on it (police car, front end collision) cost me 125, for H pipe, two mufflers with welded on tail pipes, the 4 hangers and brackets plus the two muffler clamps. They looked new.
I had to add the 3 bolts, self tapping 8 mm bolts for the holes in the driver's side.
I was working under a low rise lift. The job would be easier on Jack stands, if they were very tall.
Much easier on a two post lift, but I don't have one, and I'm too old and lazy to put out the jacks stands, so I worked with only 24 inches of clearance.
You do NOT have to pull the rear end, despite so many muffler shops, etc. assuring me it had to be that, or cut the pipes, then re-weld them.
I had to lift the car, remove the tires, and unbolt the bottom of the shocks (using a transmission jack under the pumpkin.
Then I compressed (slightly) and removed the coil springs, mostly to get more room.
I had to unfasten the outer end of the rear positioning arm.
I then marked and unbolted the drive shaft at the rear, 12 point socket 12mm.
I used a bungee cord to anchor the shaft up and out of the way. There is a place there that seems like it was designed to do that. Don't know what the holes are for, but the bungee cord fit perfectly.
The four bolts to remove the dampener weights and the front exhaust brackets from the rear cats came right off, pipe warm, with a little PB blaster.
I spent 6 bucks for the two new flange gaskets, but truthfully the old ones would have worked.
The Y pipe did not want to come out of the muffler. Since I was not going to use the Y pipe, and was putting in a new muffler, I just a tubing cutter to cut the pipe just in front of the muffler.
To remove the muffler, with tailpipe still installed, I wrapped the end of the tailpipe in cloth (so I wouldn't hit the paint, that thing is clumsy) then worked it out forward, and at an angle.
The new, identical but shinny, right side half of the dual pipes went in from the front, twisting and working it in. No scrapes, just finicky positions.
Note, on the Passenger side, the tail pipe goes OVER the centering brace. On the Driver's side, it goes under.
Fumbled with that for a few minutes, trying to make them pass the same way. Then my wife helpfully pointed out, the passenger and driver braces are bent differently to accommodate the pipe. Whoops.
I had to use a pipe expander to take the compression ring off each of the mufflers.
A cheap HF worked fine, I had to be careful not to over expand them.
Steel wool to polish up the H pipe inserts so they slid in easy.
I have not driven the car yet, but it sounds almost the same on the lift.
I wasn't looking for more noise, but just trying to get the engine a little more pep.
So anyone looking to upgrade from single to dual, you really just need the h pipe and driver's side tailpipe and muffler, plus three 8 mm self tapping bolts.
Easy upgrade.
Police and taxi cab exhaust for those years look exactly the same, as the small breaker yard I dealt with had lots of both, and you could not tell the difference.