2 cats?
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2 cats?
1990 351 EFI Bronco
Just curious. Do i have 2 stock cats or 1? There's one after the y pipe with a heat shield, then goes downstream where a section of exhaust is covered again with a heatshield. I think I see air injection tube goes in just before here from the engine. Then it goes to the muffler.
Ive been told only 1, but i think that second one makes it 2.
Just curious. Do i have 2 stock cats or 1? There's one after the y pipe with a heat shield, then goes downstream where a section of exhaust is covered again with a heatshield. I think I see air injection tube goes in just before here from the engine. Then it goes to the muffler.
Ive been told only 1, but i think that second one makes it 2.
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get rid of both of them and replace them with one high flow. It's legal, it will pass emmisions, its about $80.00, the stock ones choke out about 65% of your exhaust sound and and cut way down on performance. I did the same thing to my 93 and have never regreted it (it passed emmisions last week)
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2 if it's still stock. both sides of the engine combine into a y pipe which feeds into the first cat which feeds inot the second cat whick feeds into the muffler. all of which is on the passanger side right below the door. Oh and just so you know the factory cats are not identical (one is bigger)
Fleet Mechanic
Joined: Nov 2003
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From: North Dakota
I am not sure about cali, but here in Clark County you will fail if you remove one. Sometimes the smog guy does not know what he should be looking for and you will pass. I had my first one gutted and the second was replaced with a high flow catco followed by a flowmaster.
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Thanks
1990 EFI 351W
Ill try a single high flow cat. The guy at the autoparts store says the second one is a resonator, but i dont think hes right. I never heard anything here about resonators.
Ill try a single high flow cat. The guy at the autoparts store says the second one is a resonator, but i dont think hes right. I never heard anything here about resonators.
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yes Greybullit it will pass california emmisions (thats where i'm stationed). Just had mine done last week and it was waaaaaaaaaaay below the max on everything. They are 50 state legal because they do the same amount of filtering as the stock ones, but don't choke the engine. It's only illegal to remove emissions equipment if you don't replace it with the same thing or the equivalent (aftermarket highflow). HOPE THIS HELPS!
Fleet Mechanic
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From: North Dakota
I would still be careful removing one. Every county has there own emissions. It is easier to gut the first one out anyways because it serves as your y-pipe. If you remove it then you are stuck building or buying a y-pipe or a more expensive cat.
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Lattices2 if you gut one of the two stock cats, thats illegal (if you care) and i doubt it would pass emissions.
That being said i would just take it out cut open the top (so that when you put it back in you can't tell it's been altered), and just put a straight piece of exhuast pipe inside of it so that the ehuast just flows straigh through it without being interfering with it.
That being said i would just take it out cut open the top (so that when you put it back in you can't tell it's been altered), and just put a straight piece of exhuast pipe inside of it so that the ehuast just flows straigh through it without being interfering with it.