: Cat delete???



H-town_V
06-06-13, 09:49 PM
I started this conversation in another thread but figured I would make a new one cuz I really want some answers

Here's the original post,

Originally Posted by RyRidesMotoX
The stock cats bolt onto the exhaust manifolds and onto the rest of the exhaust as I recall so you can just grab a matching flanges and weld it up to some exhaust piping and your good... It will help with performance a bit, cats are fairly restrictive. But it will sound a lot better as well. If you get new flanges you can just run no cats most of the time then if you have to smog it you can bolt the cats back on.

(My post below)
Man you just opened up my mind to a completely new idea. I already have a magnaflow cat back and I like it but I wish it had a Lil more rumble.

Because of were I live I just can't add headers, it would be to loud. I had to sell my 06 titan w/l LT headers and true dual exhaust Cuz the condo unit was trying to kick me out. I live in a 55+ age condo unit that my parents own (i rent)and the board members just let me stay is long as I'm not to noisy.

I didn't realize the factory cat setup could simply be unbolted (on my truck the cats were welded onto the manifolds). So my plan now is to have my exhaust shop just replace the cat setup from the manifold to the x pipe with a 2.5 inch straight pipe. That way I could always go back to factory in order to pass inspection.

The only thing I'm worried about is the added heat and stress to the factory iron manifolds. The only reason I Evan say that is because one of the factory manifolds on my titan cracked after I put a cat back exhaust on it. The I engine was running to lean/rich(I'm not sure) and it cracked.

darkman
06-06-13, 10:19 PM
If you replace you cats with pipes you will presumably need to have at least front O2 sensors installed in the "pipes" using welded on bungs. I see no reason why such a setup would burden your exhaust manifolds in terms of added heat. (Cats run hotter than the rest of exhaust downstream of the manifolds.)

(I have RT high flow cats, which have all four O2 sensors - the post-cat sensors are tuned off in the tune.)

Twitch
06-06-13, 10:21 PM
I had a set of RT hi-flo cats with my Magnaflow cat-back. The cats got burned up and I basically ended up with what your looking to do. Ran it like that all of last summer without anything cracking. You should get it tuned to have it run right but you can do without if your not that picky.
In my opinion the car sounded great at idle (old school muscle) but was horrible going down the road. My idea of loud may be different than yours, but it was much quieter when I put stock cats back on. You might get away with it if you don't give it too much gas near the old people :rolleyes:.

I'd advise against it, but if your gonna do it, I don't think you'll have an issue with it.

Tony

darkman
06-06-13, 10:30 PM
I had a set of RT hi-flo cats with my Magnaflow cat-back. The cats got burned up and I basically ended up with what your looking to do. Ran it like that all of last summer without anything cracking. You should get it tuned to have it run right but you can do without if your not that picky.
In my opinion the car sounded great at idle (old school muscle) but was horrible going down the road. My idea of loud may be different than yours, but it was much quieter when I put stock cats back on. You might get away with it if you don't give it too much gas near the old people :rolleyes:.

I'd advise against it, but if your gonna do it, I don't think you'll have an issue with it.

Tony

Does that suggest that my RT cats are destined to fail? (I am tuned, and to me they seem to run cooler than the OEMS, but that may be just because they have more clearance as I have not actually measured any temps.)

H-town_V
06-06-13, 10:34 PM
My #2 idea is to replace the factory b pipe with one that has a hi flow cat welded in.

And getting my car tuned is not an issue so ill do it after any mods.

Hi flow cats would add about $200 to this project so if it won't hurt anything I'd rather go without.

Twitch
06-06-13, 11:03 PM
Does that suggest that my RT cats are destined to fail? (I am tuned, and to me they seem to run cooler than the OEMS, but that may be just because they have more clearance as I have not actually measured any temps.)
I'm assuming the blower did them in.


My #2 idea is to replace the factory b pipe with one that has a hi flow cat welded in.

And getting my car tuned is not an issue so ill do it after any mods.

Hi flow cats would add about $200 to this project so if it won't hurt anything I'd rather go without.
I doubt it'll hurt anything. I just hated the way the car sounded.

darkman
06-06-13, 11:07 PM
I'm assuming the blower did them in.

Could be. I wonder if those with blowers running high-flow cats behind headers have, or will have, the same problem.

H-town_V
06-06-13, 11:13 PM
I'm assuming the blower did them in.

I doubt it'll hurt anything. I just hated the way the car sounded.

Can you describe the sound and why you hated it so much...was there excessive drone, lots of popping & crackling or was it just to loud?

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Your car has a blower?? I'm sure that affects the sound.

brngrhd
06-06-13, 11:25 PM
Could be. I wonder if those with blowers running high-flow cats behind headers have, or will have, the same problem.

Well that's probably what killed my stock cats since I only have 43k on the car LOL

BigDaddy-V
06-07-13, 12:36 AM
Hey Darkman,

Are you running factory location of your RT cats? Just wondering and also trying to come up with different placement options for when I move mine around.

BDV

darkman
06-07-13, 07:50 AM
Hey Darkman,

Are you running factory location of your RT cats? Just wondering and also trying to come up with different placement options for when I move mine around.

BDV

The RT cats bolt in place of the OEM cats and the location is approximately the same as OEM - (there may be a few millimeters difference in the distance from the cat to the exhaust manifold, as well as a few millimeters difference in the absolute length of the cat within the pipe from OEM.) The look much like these: http://www.mandrelexhaustsystems.com/servlet/the-273/04-dsh-07-CADILLAC-CTS-dsh-V-EXHAUST/Detail. (The RT's look a little smoother and presumably have better internals, but they cost twice as much.)

barrok69
06-07-13, 09:36 AM
Could be. I wonder if those with blowers running high-flow cats behind headers have, or will have, the same problem.

I'll put this on my checklist for when I plop in a new driveshaft in a couple weeks. I also have some type of aftermarket cat, corsa, LT's and maggie.

BigDaddy-V
06-07-13, 10:41 AM
Those mandrel bent ones are the ones that got me thinking about changing my exhaust up in the first place. I am just thing about going a different route by using the magnaflow and putting it in the mid pipe like the kooks and test piping sort of where the factory cats go. I figure by moving them further downstream it will open up the flow some and I can still use all the sensors and be legal! I know it isn't the same as LTs yet and I plan on going that route and my thought was breaking up the cost a little and then just true bolt on when I do the headers but surely it helps eek out a little power.

BDV

brngrhd
06-07-13, 05:26 PM
Just removed my cats today. Sound is a little louder, not too loud at all, I love it.

H-town_V
06-08-13, 02:02 AM
Do our cars have o2 sensors after/behind the factory cats?

I just got my car tuned so I'm wondering if I'd have to get those tuned out.

................

Sry darkman I should have looked back at your post cuz you already answered my question.

BigDaddy-V
06-08-13, 02:10 AM
Yes they do. One in front and one behind on each cat. I have kicked around getting them tuned out and not messing with it but I know I would be the guy that gets caught so I want to modify but still stay legal for peace of mind.

BDV

H-town_V
06-08-13, 02:26 AM
Yes they do. One in front and one behind on each cat. I have kicked around getting them tuned out and not messing with it but I know I would be the guy that gets caught so I want to modify but still stay legal for peace of mind.

BDV

Thanks I figured they were there. How can you get caught? Do cops carry co2 sensors around. Here in Texas lots of people drive trucks with straight pipes that are just stupid loud and the cops don't do shit. I'm not worried about the smell either I have a 92 c1500 with no cats.


114721

Twitch
06-08-13, 02:42 AM
Can you describe the sound and why you hated it so much...was there excessive drone, lots of popping & crackling or was it just to loud?

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Your car has a blower?? I'm sure that affects the sound.

I guess the best description is that it sounded a little like an exhaust leak.
I know it's a fine line with all the crap we do to our cars, but I didn't think it sounded "right". Others may like it. It did sound ballsie, just not for me.

RyRidesMotoX
06-08-13, 02:44 AM
Here in California they are starting emissions checkpoints... I'm not joking. Apparently testing is voluntary but I can just see that becoming a tucket magnet for this bankrupt back assward state. If a cop here wants to crawl under the car and see if you have cats, and you aren't he can give you a FAT ticket if you aren't running them. I'm just hoping that they don't want to get in the dirt.

H-town_V
06-08-13, 03:10 AM
Here in California they are starting emissions checkpoints... I'm not joking. Apparently testing is voluntary but I can just see that becoming a tucket magnet for this bankrupt back assward state. If a cop here wants to crawl under the car and see if you have cats, and you aren't he can give you a FAT ticket if you aren't running them. I'm just hoping that they don't want to get in the dirt.

Wow emissions checkpoint. It sucks you gotta give up 1/2 your rights just to live there, but you got MMJ so...

I couldn't imagine a cop trying to look under my car for cats(just the thought makes me laugh). Plus I would fight the case anyways. There's not a judge in the country that would let an emissions ticket go to trial.

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I also have a good friend that works at an exhaust shop so I'm sure he could find a pair of old cats that we could just punch out then weld in and use as dummies.

RyRidesMotoX
06-08-13, 04:24 AM
Out here they are Nazis about emissions. I almost got written up once but the cop was cool as hell. His trainee wanted to write me a fat ticket for speeding and tint and my exhaust and stuff on my old cobalt. But I knew the training officer from work encounters so he recognized me and let me off... I got lucky. Could have been a $1500 night right there.

H-town_V
06-08-13, 04:38 AM
I guess the best description is that it sounded a little like an exhaust leak.
I know it's a fine line with all the crap we do to our cars, but I didn't think it sounded "right". Others may like it. It did sound ballsie, just not for me.

I'm sure you're car having LTs and Maggie makes the "exhaust leak" noise 5x louder. I'm thinking ill go the straight pipe rought and if it's annoying I'll add some hi flows.

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Out here they are Nazis about emissions. I almost got written up once but the cop was cool as hell. His trainee wanted to write me a fat ticket for speeding and tint and my exhaust and stuff on my old cobalt. But I knew the training officer from work encounters so he recognized me and let me off... I got lucky. Could have been a $1500 night right there.

That sucks your state is so worried about BS. I'm not saying our cops are saints or anything but they usually don't sweat the small shit. Although a buddy of mine got his car towed/impounded cuz cops said his(5%) tent was too dark to safely be driving at night.

RyRidesMotoX
06-08-13, 05:11 AM
I had 5% tint on my car at the time. I wouldn't even argue about that ticket lol. But I pulled over knowing my car would have easily outran them, and they probably had backup like 15 minutes away, and I know the back roads there so well from living there all my life... I would have been pissed if they wrote me up. My dad's buddy has a supercharged Z06 C5 with like 600whp and he was racing a viper once on the freeway... There was a cop that pulled out... By the time he even got on the highway the vette and viper we forever ahead... Like 130-140mph+ easy... My dads buddy saw these lights waaaaaaay back in the distance and he pulled over... The cop stopped behind him and ended up just letting him off. His exact words- "I don't know why you stopped I would have never caught you. But for being a good sport about it you can have a good night. Don't do that shit anymore" and he walked away. We have some cool cops here too but we also have SUPER douchebags.

BigDaddy-V
06-08-13, 10:18 AM
I probably wouldn't get caught but it is the thought that haunts. That truck of yours looks real sweet. My first was a 91 GMC short wide 350 5 speed black and it didn't have cats and then on one of my inspections they looked and it failed! Since then I have always had it in the back of my mind. Plus with our cars I still want it to have the sleeper effect and an element of surprise!

BDV

H-town_V
06-08-13, 12:58 PM
I probably wouldn't get caught but it is the thought that haunts. That truck of yours looks real sweet. My first was a 91 GMC short wide 350 5 speed black and it didn't have cats and then on one of my inspections they looked and it failed! Since then I have always had it in the back of my mind. Plus with our cars I still want it to have the sleeper effect and an element of surprise!

BDV
Thanks BDV

Yea living In Texas you gotta keep at least one truck. And it's in amazing condition,my dad bought it new in 1992. When I got it 2 years ago it only had 92k miles and only has 105k now. Best trucks ever IMO.

BigDaddy-V
06-08-13, 05:25 PM
Yes I agree with you! I had to trade in my 2000 sierra extended cab that I had done like every bolt on to get my V but still have an 04 Burban that I plan on tweaking when it isn't the wife's daily driver. I would love to have my first truck back and just do an LS swap on it but oh well. That is a project for later in life. Me and my dad are rebuilding a 75 Stingray from the frame up and having fun with that one right now. I think you were right about those trucks being the best but I sure did enjoy my 2000!

BDV

H-town_V
06-08-13, 07:40 PM
Yes I agree with you! I had to trade in my 2000 sierra extended cab that I had done like every bolt on to get my V but still have an 04 Burban that I plan on tweaking when it isn't the wife's daily driver. I would love to have my first truck back and just do an LS swap on it but oh well. That is a project for later in life. Me and my dad are rebuilding a 75 Stingray from the frame up and having fun with that one right now. I think you were right about those trucks being the best but I sure did enjoy my 2000!

BDV

I bought that truck from my dad for $2000. I've since had cash offers as high as $8000.

I won't/can't ever sell that truck, that's the one agreement my dad made with me. I also wanna do a ls/vortec swap at some point. Since its over 20 years old I don't have todo emission testing so mod options are endless.

BigDaddy-V
06-08-13, 07:49 PM
Oh man that is a sweet deal! If it ever comes down to it and you need to I would take care of it for you! It looks crazy clean still! Let's get this thing figured out about our cats and placements of them and maybe help out some others in the process! Keep on posting what you do and I will do the same once I talk to another shop this week and see what he thinks of my ideas.

BDV

ONEBADCADDIE
06-08-13, 08:13 PM
Come to Florida. They don't care about anything..no emissions. It's lovely. Only issue I have is a may be moving back to Massachusetts in the near future so I'm still torn between the CAT removal.

H-town_V
06-10-13, 04:05 PM
So I'm deff going the straight pipe no cat rout first just to see how I like it. Ill get a o2 bung welded in and just have the rear ones turned off. If I don't like it ill just weld some magnaflow hi-flows in.

I do have a question tho. My plan is to run cat less for 99% of the time then put the factory setup back on In order to pass inspection. But will I still pass if my rear o2 sensors are turned of. Ill put a bung plug(hehe) or big bolt in we're the rear 02 hole is. Will this pass inspection. Or do I have to have all 4 o2 sensors working?

darkman
06-10-13, 07:19 PM
So I'm deff going the straight pipe no cat rout first just to see how I like it. Ill get a o2 bung welded in and just have the rear ones turned off. If I don't like it ill just weld some magnaflow hi-flows in.

I do have a question tho. My plan is to run cat less for 99% of the time then put the factory setup back on In order to pass inspection. But will I still pass if my rear o2 sensors are turned of. Ill put a bung plug(hehe) or big bolt in we're the rear 02 hole is. Will this pass inspection. Or do I have to have all 4 o2 sensors working?

You should be able to pass inspection with the two O2 sensors turned off. The only reason to have the two rear sensors physically on the pipe/or cat is the outside chance an over enthusiastic inspector crawls under the car.

H-town_V
06-11-13, 02:00 AM
You should be able to pass inspection with the two O2 sensors turned off. The only reason to have the two rear sensors physically on the pipe/or cat is the outside chance an over enthusiastic inspector crawls under the car.

Cool. I kinda figured but your reply makes me confident it won't be a problem. Plus I've been getting my cars/trucks/motorcycles inspected at the same shop for at least 8 years. And in the past they have let some very obvious fails just pass.

BigDaddy-V
06-11-13, 09:32 AM
Not that I don't want to be legal but I need to get me a shop like that up here! Have you made any changes yet?

BDV

H-town_V
06-11-13, 11:56 AM
Not that I don't want to be legal but I need to get me a shop like that up here! Have you made any changes yet?

BDV

Not yet. My cars interior is all ripped apart right now. I'm having some accent pieces hydro dipped(I got another thread going about it in the appearance mod section). So I'm trying todo just one thing at a time. I know the exhaust is completely different than the interior, I just wanna get this(hydro dip) done first.

Ill prob do the cat delete next week, only problem is the shop I go to is about an hour from were I live now, so it's basically an all day ordeal for me.