Need to Add Cats, help please!
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Launching!
Joined: Mar 2008
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Need to Add Cats, help please! Hi guys, i should be getting my trans am soon that I just bought. It has true duals with no cats but dyomax mufflers. In my city (Vancouver, B.C., Canada) there is a visual for cats and an obd test and as long as no codes you pass. Now the car is an 02 ws6, heads, cam, lts, tuned etc. Im pretty sure it has the air delete, so can I simply put some hi-flow cats on?? (im thinking magnaflow carsound ones).
I heard that the AIR is only used at the start up to get the cats heated up faster so that the cats start cleaning the emissions quicker but once the car is warmed up that the AIR doesnt really do much. Is this true?
I need cats, not only for the visual but I think the car is gonna sound pretty mean and nasty even at idle so i need to tone it down abit theres alot of cops in this damn city, and cars that have head/cam packages seem to be pretty rare, even just longtubes arent that common so i will stand out lol.
Basically can i slip on/weld some hi flow cats on for the visual and to kill my sound abit and not worry about anything else, or do i have to worry about the AIR system, hooking and setting up 02 sensors, re-tuning the car for cats, etc etc.
I heard that the AIR is only used at the start up to get the cats heated up faster so that the cats start cleaning the emissions quicker but once the car is warmed up that the AIR doesnt really do much. Is this true?
I need cats, not only for the visual but I think the car is gonna sound pretty mean and nasty even at idle so i need to tone it down abit theres alot of cops in this damn city, and cars that have head/cam packages seem to be pretty rare, even just longtubes arent that common so i will stand out lol.
Basically can i slip on/weld some hi flow cats on for the visual and to kill my sound abit and not worry about anything else, or do i have to worry about the AIR system, hooking and setting up 02 sensors, re-tuning the car for cats, etc etc.
The f-body never had air tubes TO the cats, if thats what you're asking about. They went into the manifolds. So yes, you can add cats no problem. If its been tuned, all the codes for those have been turned off anyways so you won't get an SES light.
Thread Starter
Launching!
Joined: Mar 2008
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ok thanks for the response, i got the car its awesome. The car has been tuned for no cats though, it still does have the rear 02 sensors and NO engine check light. When I add the cats do i have to put the front 02 sensors on aswell AND retune it? Or can i just stick the cats on with no front 02s and just use the tune from before when it didnt have cats??
When the cats were removed, they deleted the rear O2s, you still have front ones. Just put the cats in the Y behind the O2s and you'll be fine. It should not require a re-tune.
i'm adding cats to my car eventually too. only thing that scares me is that removing cats/adding headers causes the car to run rich; so when i got it tuned, they leaned it out a bit. now when i add cats again, i'm afraid that might cause it to run even leaner.
the only reason the car will run rich after a LT-install is the changed position(further back) of the front most 02 sensors(the ones the computer utilizes to correct fueling) if your adding cats to your LT setup your A/F ratio will not change..... so yes you can just weld some cats right up
if your changing back from longtubes to stock manifolds then you may/may not need a re-tune.
You guys just need to find a friend at somewhere that does emissions, so they won't visually check for codes. Easy for me, I used to work at a few of the places here in town so I have lots of friends
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If you do not want to worry about it running rich or lean just buy a cheap set of normal cats, and punch them out you will pass the visual and you will pass the obd test. Just buy a set of used cats that are the same size piping as your exhaust and get a crow bar and a mallet and hit hit and hit... then band clamp them in or weld them in and your set.
I have my cats band clamped in, when i got my exhaust done they were going to make straight pipes that are the same bend and length of my cat piece so i can just take my cats off and band clamp the straight pipe in and then when i need inspected and emissions i can unbandclamp the straight pipes and clamp the cats back in.. But my car was loud enough that i just kept the cats, it sounds perfect they were going to make the straight pipes and all for 50 bucks thats a hell of alot cheaper than buying a dummy set of cats, or punching out the high flow cats i just paid good money for... there is another option buy the cats and get pipes welded on the cats so they are exactly the same as the straight pipe pieces and just switch them out for emissions...
I have my cats band clamped in, when i got my exhaust done they were going to make straight pipes that are the same bend and length of my cat piece so i can just take my cats off and band clamp the straight pipe in and then when i need inspected and emissions i can unbandclamp the straight pipes and clamp the cats back in.. But my car was loud enough that i just kept the cats, it sounds perfect they were going to make the straight pipes and all for 50 bucks thats a hell of alot cheaper than buying a dummy set of cats, or punching out the high flow cats i just paid good money for... there is another option buy the cats and get pipes welded on the cats so they are exactly the same as the straight pipe pieces and just switch them out for emissions...
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Verdad Gallardo If you get a nice set of high flow cats like myself.... your only loosing about 1-2hp per cat... the pros to a catted system outweigh gutted cats.
- they give back some low end torque...
- your car wont smell like gas all the time
- never have to worry about visual inspection
I can PM you a site that sells my cats really cheap and they breathe very well..
just as a reference i made 342hp/351 tq with these cats with longtubes, borla, slp lid and ls6 intake...... basic boltons
125 shot 490hp/551tq...... you wont regret having cats if you chose to buy them
- they give back some low end torque...
- your car wont smell like gas all the time
- never have to worry about visual inspection
I can PM you a site that sells my cats really cheap and they breathe very well..
just as a reference i made 342hp/351 tq with these cats with longtubes, borla, slp lid and ls6 intake...... basic boltons
125 shot 490hp/551tq...... you wont regret having cats if you chose to buy them
TECH Apprentice
Joined: Nov 2004
Posts: 300
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From: Kitchener, Ontario, Canada
Good old emmissions testing. You should feel lucky. Air Care is better than Drive Clean in Ontario. We don't have a visual but we all have to do the sniffer test. I actually got mine to pass this past year with my cam and wee little cats that came in the TSP y pipe. You wont need the air system, your right it only come on at idle and when cold. I recommend Magnaflow's metal susbtrate cats. They are supposed to flow a bit better than regular ones and they work well too.
I wish I could get away with a scan test and a visual.
I wish I could get away with a scan test and a visual.
With Lt's Catted Y-Pipe, Custom Catback, Slp Lid, Ls6 Intake, Pnp TB i made 350hp/360Tq And with the cutout open I did not lose any HP or TQ at any RPM this could be because of the Cats Thats why i would not worry about the cats I left them on when i had the chance to take them off
With Lt's Catted Y-Pipe, Custom Catback, Slp Lid, Ls6 Intake, Pnp TB i made 350hp/360Tq And with the cutout open I did not lose any HP or TQ at any RPM this could be because of the Cats Thats why i would not worry about the cats I left them on when i had the chance to take them off
p.s. your gonna love that HSW kit! im running a 125 shot now
Thread Starter
Launching!
Joined: Mar 2008
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ya they wont fail on the longtubes, i know lots of people with longtubes, even a guy with a loud ford lightning. Its literally a obd codes check, a visual for a cat and the fuel filler pressue check.
Ok so i got pacesetter longtubes, then the tsp true duals then the front 02's, then dynomax bullet mufflers, then piping to an x pipe, then a bit more piping and then dumped. So basically RIGHT after the longtubes and after the 02s (to prevent any obd codes) jus cut and weld the cats then cut off and throw away the same amount of straight piping so that the total length will be exactly the same right??
I need the cats on permanently, the car is wayyyyyyyy to loud right now it sounds like a ****** drag car lol, i love it but too heaty, wayyyy too heaty arond here.
So does that sound about right?
Oh, now that I got cats it still wont throw any obd codes cause the cats will be added AFTER the front o2s and it has no rear 02s, is that right???
Ok so i got pacesetter longtubes, then the tsp true duals then the front 02's, then dynomax bullet mufflers, then piping to an x pipe, then a bit more piping and then dumped. So basically RIGHT after the longtubes and after the 02s (to prevent any obd codes) jus cut and weld the cats then cut off and throw away the same amount of straight piping so that the total length will be exactly the same right??
I need the cats on permanently, the car is wayyyyyyyy to loud right now it sounds like a ****** drag car lol, i love it but too heaty, wayyyy too heaty arond here.
So does that sound about right?
Oh, now that I got cats it still wont throw any obd codes cause the cats will be added AFTER the front o2s and it has no rear 02s, is that right???
Thread Starter
Launching!
Joined: Mar 2008
Posts: 262
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does anyone know what kind of magnaflow hi-flow cat to use for the true duals?? There are the 9500 series, 8700, 8900, 9100, etc etc etc and they just about all come in 2.5" or 3" and theres lots of different models of each series. Im so lost.
Thread Starter
Launching!
Joined: Mar 2008
Posts: 262
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If you get a nice set of high flow cats like myself.... your only loosing about 1-2hp per cat... the pros to a catted system outweigh gutted cats.
- they give back some low end torque...
- your car wont smell like gas all the time
- never have to worry about visual inspection
I can PM you a site that sells my cats really cheap and they breathe very well..
just as a reference i made 342hp/351 tq with these cats with longtubes, borla, slp lid and ls6 intake...... basic boltons
125 shot 490hp/551tq...... you wont regret having cats if you chose to buy them
- they give back some low end torque...
- your car wont smell like gas all the time
- never have to worry about visual inspection
I can PM you a site that sells my cats really cheap and they breathe very well..
just as a reference i made 342hp/351 tq with these cats with longtubes, borla, slp lid and ls6 intake...... basic boltons
125 shot 490hp/551tq...... you wont regret having cats if you chose to buy them
Hey I was wondering if i can get more info on those cats? Are they like bullet shaped and wont really decrease the clearance or are they the ones that really bulge out??
