View Full Version : Exhaust that will pass emissions

01-25-2006, 12:35 AM
I found a small exhaust leak behind the driver's door, somewhere between the catalytic's and the mufflers. The muffler will need to replaced soon and the catalytics (they rattle sometimes) are most likely original with 125k on them. Its not that bad, I was just wondering what I could get away with if I was going to replace the exhaust. I was going to go the same route (mustang headers, h-pipe, 2.25 or 2.5 tail pipes, and decent mufflers) exhaust wise as most CV/GM/TC owners do, but my car still has to go through PA emissions. The car passed emissions with flying colors last year with bad timing, bad spark plugs and wires, and an old air filter though. Now, all those issues have been cleared up and it runs like a top.

01-25-2006, 01:13 AM
My Car passes emissions in chester county with no problem. I run stock mustang manifolds and a stock H-pipe. I fabbed up some brass tubing for the air lines but I dont think anyone would notice at an inspection place.

01-25-2006, 01:53 AM
Just do catted H pipes and it should be fine. Unless they're anal I doubt they'd look for the air pipes, but you can just snag one off a Mustang or Mark VII and use it, or get the silicone tubing and use to tie the diverter valve into the air lines to the cats. Some aftermarket cats don't have those lines anyway so you can probably get away without them. New style catalysts don't need the extra air and newer engines don't have a smog pump anyway. I have a Mark VII air pipe if you want it.

01-25-2006, 12:24 PM
Does the mustang catted h-pipe fit without any problems, except requiring mustang headers? I was looking into catted h-pipes also, but the cheapest I found was $260 without shipping. At the shop I take it to, they aren't too picky on emissions equipment and will pass your car if it passes the emissions test. I was hoping that maybe I could get away with punched out cats since the heads and headers are restrictive, but I doubt it.

Also, if I replace the catalytics would it be loud with duals and no mufflers? I've been looking into a louder dual exhaust setup, but I don't want a setup that will drone on the highway. My friend's 05 F150 with the 5.4 liter V8 running a gibson cat back exhaust tends to drone very loudly whenever he is at a steady highway speed.

Grand Marquis GT
01-25-2006, 12:55 PM
Could always go see scott (lincolnmania)...

I have an offroad H with side exits (glasspacks) and shortie headers, and it doesnt really drone, and you could pull it off since you have a 2dr...

01-25-2006, 01:47 PM
I have an HO converted 89 Lincoln, with stock mustang headers and a stock mustang H-pipe with new cats, and it is LOUD AS HELL with no mufflers. I got it to fit up there just fine no probs there, and I got it for $100 from a local guy.

01-25-2006, 03:36 PM
unfortunately your car will fail emmisions with punched out cats.......it will fail nox (oxides of nitrogen) without the catylist in place.........check on the mustang boards for a catted factory h pipe.......i have a set of stock stang shorties if you need.........to hook the mustang h pipe to the mufflers you will need two napa pipes, part number 43281, and two mid pipe flanges for a 87-93 mustang............the pipes are for a chevy truck, but they fit well
let me know if you need some help with your project, my shop is a little over two hrs from philly and my house is an hr from philly

01-25-2006, 07:55 PM
Thanks scott, I'll check the mustang forums for a catted h-pipe. Im going to take another look at my exhaust either this weekend or next weekend to try to get a better idea on what needs to be replaced. Thanks for your offer to help, I might try to bring my car to your shop if I end up replacing the exhaust. Im up at Kutztown University, so I don't know how far I'm away from your shop though.

01-25-2006, 08:15 PM
He's up in Schuychill County, near Pottsville, right about where 81 and 209 cross if that gives you any hint.