Cats and Cutouts?

**lvbroham1** · 12-30-2008, 09:04 AM

I'm fabing up a 3 inch true dual system and have to run cats to pass inspection.

I was wondering is it wise to put cutouts before the cats or after? I've ordered the DMH low profiles and am going to run magnaflow hi-flow cats 59959's then over the axle and a magnaflow muffler. As far as I know there is no requirements on where cutouts are allowed, just that they have to be closed on the street. I've seen systems with the cutouts after the cats, but have never seen one with cutouts before the cats. Any suggestions?... Oh! and thanks in advance!!!!

**GULLETT17** · 12-30-2008, 09:52 AM

performance wise, i would think putting them before the cats would be more beneficial.

**lvbroham1** · 12-30-2008, 10:15 AM

See, I thought the same thing, it's just i haven't seen someone do it before. All that i've looked at have the cutouts after

**GULLETT17** · 12-30-2008, 10:20 AM

well where i live they arent strict on emmissions so i dont have much experience with what they pass or dont pass. the only reason i could think that you havent seen it before the cats is that they dont allow it that way. i dont think the cutouts would have an effect on the emissions when closed tho.

**sunsetorangess** · 12-30-2008, 12:25 PM

For performance i would say befor the cats would benefit ya the most. Call your local inspection station and see what they say. Everystate has different rules and regs about emissions.
J

**lvbroham1** · 12-30-2008, 12:47 PM

I'll probably end up doing that, I talked to a buddy of mine and he says guys do cutouts after cats so the car won't throw a code if you open them up. He says that if you have them pre cat and don't have the rear o2's deleted, most likely every time you open them up you're gonna see the ses light. I have the rear o2's deleted, so I don't think that'll be an issue for me, just need them for inspection.

**GULLETT17** · 12-30-2008, 12:53 PM

Originally Posted by lvbroham1

I'll probably end up doing that, I talked to a buddy of mine and he says guys do cutouts after cats so the car won't throw a code if you open them up. He says that if you have them pre cat and don't have the rear o2's deleted, most likely every time you open them up you're gonna see the ses light. I have the rear o2's deleted, so I don't think that'll be an issue for me, just need them for inspection.

i can definately see it throwin a code . . . just get the o2's deleted.

**lvbroham1** · 12-30-2008, 12:59 PM

I think i'm just gonna weld in some bungs and connect the rear o2's even though they are deleted for inspection purposes only. I'm leaning to doing the cutouts before the cats, but i'm gonna check with an inspection place first.

**grouch0jr** · 12-30-2008, 01:38 PM

Originally Posted by lvbroham1

See, I thought the same thing, it's just i haven't seen someone do it before. All that i've looked at have the cutouts after

well, do you have LTs yet? if not, and youre running stock manifolds, youre going to ahve to put the cut outs after the cats... otherwise, definitely do the cut outs before the cats. more noise better performance.

**lvbroham1** · 12-30-2008, 03:47 PM

Yea, I already have pacesetters, ory, and a LM1.

**grouch0jr** · 12-30-2008, 09:25 PM

haha, ORY with the LM1 isnt loud enough for you?

some people say that cut outs may hurt performance due to lack of back pressure.

**lvbroham1** · 12-31-2008, 04:31 AM

Oh It sounds sweet, but due to the emissions where i'm at I need to get cats, so I figured I'd take on the task of true duals. I plan on quieting the car down a little with the cats and a magnaflow muffler, the LM1 was great before I did heads and a cam, now it's rediculously loud. I'm looking for a more mellow tone and than ear piercing at WOT, and cutouts for the track whenever I decide to go lol