kstinson

When I purchased my LX it had what appears to be a Flowmaster exhaust with straight pipes instead of mufflers. I am currently replacing the aftermarket cats because the car will not pass emissions and the A.I.R. is only hooked into the passenger converter. The question is even with the new cats and h-pipe is the car going to pass with straight pipes? I don't know if the lack of backpressure is going to cause the converters to loose heat or not. The car is very loud and pops on deceleration. I have tried everything to make the car pass but it seems to be the lack of air to the drivers side converter causing it. Plugs are clean but the test says that it is rich, go figure. Any exhaust people have any opinions?

cammedlx

i would'nt think havening no mufflers would effect emissions cause i had a 97 stang with a stock mid pipe with no mufflers and it passed just fine but i really could'nt tell maybe mine was just by luck hard telling

roundman

is the smog pump hooked up and functioning properly? if this ain't working right, it will make the exhaust gas be richer than it should be. also what about the EGR valve system?
bad O2 sensors will also contribute to a over rich condition so you might think about changin them too.

Big5.0.13.7sec.

Not having the mufflers should not make you fail the emissions test!

My car only has the pump, going to the passanger convertor... i think that is how it is supposed ot be! Someone, anyone corretc me if I am wrong....

Im going to go with roundman on this one! Make sure the pump is working! And the egr valve system is working!

And seeing the car is old like al 5.0's are (OBVIOUSLY) the person who had the car b 4 u probably never changed the o2's.

I went to change mine when I first got my car... and they looked damn old.. maybe even the original. Took a lot of muscle and pounding to get those out. I'd say yours need changed as well....

luckythirteen13

my pump has a tube that runs to both of the rear cats

nemethjames1

i gotta 88gt straight pipe, passes smog everytime, the only reason why your car wouldnt pass with straight pipe is/.... if the smog check guy was an ******* and seen no mufflers he could fail you for visual inspection

xc_ute

Under Federal and the laws of many states NOT HAVING operational, factory installed anti-smog equipment (or certified replacement parts) is automatic failure.

And you are worried about straight pipes?

kstinson

I was just wondering if the lack of mufflers would cause the catalytic converters to lose heat and not function properly. The pipe that was on the car only sent air to the passenger side converter but I just picked up a used stock h-pipe from a Mustang shop here and they said the 4-converter h-pipe from the factory with air going to both rear converters will give my car the best chance. I am installing the factory h-pipe tonight. As for the air only going to one converter I highly doubt that it is the factory pipe, mine is like that and the pipe is clearly not a factory piece (exhaust leaks from crappy welding.) Hopefully my car will finally pass.

nemethjames1

yea, but like i said, you can pass the sniffer without mufflers, but not the visual... the visual does not always matter, only if the guy wants to really look around and write you up for it... you could leave it straight pipe and i bet you'll pass... mines been passing for around 4 years

xc_ute

Suprized that the Mustang shop didn't enlighten you on the fact that the 1987 "H" pipe from the factory only had air injected into one pipe, the right side. I don't know how many model years that pipe was used before the other side received air injection.

Even if you do go to the "H" pipe with two air fittings there is no reason to believe you will pass emissions testing. The computer in your vehicle is set up for the original "H" pipe configuration and that's the standards the emissions test is set for.

The testing companies don't pay their employees to think, they look up the emissions standards for the year of your car and that's what you have to meet. I do remember a case where a highly modified car (12:1 compression ration, water injection, etc.) which tested with less then half the emissions output of a stock vehicle, failed because it was modified and no other reason.

Another sore point, undr Federal law a certain precentage of vehicles MUST fail the tests. That means if you car passes with flying colors it would still "fail" because the tested hadn't met the required number of failures that month. In other words don't ****-off the guy doing the tests.

Or, in case you haven't heard this story, put a bottle of Jim Beam into your car before going for the emissions test. That improves the chances that it will pass. (Think about it)