I want to run dual exhaust on my 85 Grand Marquis, but I thought I remember reading somewhere that there were issues with lean conditions after that. So who has done it successfully? And would you relate your experiences please?
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CFI and dual exhaust-will it run too lean?
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it will work fine as long as you keep the cast iron manifolds or you use 90 town car manifolds or stock mustang shorty headers.
2" would be the best size for a stock engine
1986 lincoln towncar signature series. 5.0 HO with thumper performance ported e7 heads, 1.7 roller rockers, warm air intake, 65mm throttle body, 1/2" intake spacer, ported intakes, 3.73 rear with trac lock, 98-02 front brake conversion, 92-97 rear disc conversion, 1" rear swaybar, 1 3/16" front swaybar, 16" wheels and tires, loud ass stereo system, badass cb, best time to date 15.94 at 87 mph. lots of mods in the works 221.8 rwhp 278 rwt
2006 Lincoln Town Car Signature. Stock for now
1989 Ford F-250 4x4 much much more to come, sefi converted so far.
1986 Toyota pickup with LSC wheels and 225/60/16 tires.
2008 Hyundai Elantra future Revcon toad
1987 TriBurner and 1986 Alaska stokers keeping me warm. (and some pesky oil heat)
please be patient, rebuilding an empire!
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Nothing will need adjusting if you're not changing the headers. The computer should be able to compensate for dual exaust without issue. If you're doing a cat-back setup (remove the Y pipe, put in H-pipe and driver side muffler/tail)... then you're fine without any tuning.
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
Originally posted by gadget73... and it should all work like magic and unicorns and stuff.Originally posted by dmccaigOverhead, some poor bastards are flying in airplanes.
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My '84 CV was converted to duals way back in the late 80's by my Dad and it remains like that today with over 400K on it. Stock exhaust manifolds/pipes used. No issues, so go for it.These are highly engineered precision vehicles, the first step in diagnosing the problem is to strike the suspected offending part sharply and repeatedly with a blunt object, then re-test.
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You can use a newer 92-94 H-pipe no problems.1990 Country Squire - weekend cruiser, next project
1988 Crown Vic LTD Wagon - waiting in the wings
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the heads and intake can't move enough extra air for dual exhaust to make it run lean anyway.86 Lincoln Town Car (Galactica).
5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley
91 Lincoln Mark VII LSC grandpa spec white and cranberry
1984 Lincoln Continental TurboDiesel - rolls coal
Originally posted by phayzer5
I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers
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Originally posted by 86VickyLX View PostThe ECM doesn't care what you're running past the O2 sensors.
There are all sorts of reasons why that might happen and they basically all come back to a design that doesn't scale well, and that's kind of whatever.
I never did check mine for codes after going dual...
OP: the correct direct-fit H pipe is a Walker 40483. It is kind of hard to find now, but RockAuto just started indicating they can get it again, with a delay, which probably means it's built to order by Walker. The price isn't pretty compared to what they used to be, either. The box Lincoln one is 40492 - it's longer because the Lincolns are longer. It won't fit at the muffler end without some hackery, but depending on what you're running for mufflers, it might be easy to make fit.
Reports that you can use an Aero H-pipe are something I tried to figure out some time back and the answer looked like it was probably no, because the exit pipes on the cats were not positioned quite right. I'd love to know with 100% certainty that they'll fit if that's the case.Last edited by kishy; 12-23-2019, 01:53 PM.
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Thank you for that info and the part number! After doing a bit of research, I learned that AP Exhaust still makes an h-pipe for it. Their part number is 93950. Has anyone used this kit? https://www.macautoparts.net/80-88-f...st-super-turbo
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As long as your existing muffler and tail pipe are in good condition you could always buy just the h pipe, muffler and drivers side tail pipe and save some money. The only issue you’ll run into is finding a way to hang the tail pipe on the drivers side. The original part is long since discontinued and even the alternate bracket with the hook and rubber hanger has been out of production for years. Now if you took it to a shop they could fab something up no problem.
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I think I am going to just have to take it to a muffler shop anyway. I finally crawled under it and looked around. Someone cut off the factory flanges behind the cats and welded up a new y pipe, so just bolting up the oe duals is out of the question. Does anyone know if I can remove the cats without any ill affects? I wouldn't normally do this, but the air tube coming from the air pump is rusted off at the cat. I wouldn't mind just getting rid of the whole air system and the cats if I could. I thought I had read somewhere that if you had a one-wire non-heated oxygen sensor, removing the cats would make it fail to work correctly because of the lack of heat. Anyone know?
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