Time to loose the Secondary Cats!!!

[Shandon]

Ok, I have decided to get rid of the secondary cats now . I already have the Corsa Exhaust system and Love it! I want to get rid of the heat and want louder! My question is when it comes to Cats whats what? Random Tech Cats seem to be the prefered choice for these cars "maybe?"but the thing I don't know about is the substrate? Metal or Ceramic? Whats the difference and what would make me lean to one or the other?

(Yes I know I will need the 2.5"/3" adapter for my corsa)

 

[viperbob]

If you are just planning to eliminate the secondary cats do just that - no need to replace them with different cats. I assume you'll have the primary pair of cats in place so no need to worry about throwing any codes, etc. You will notice a lot cooler cockpit and save money to boot.

 

[Nsane1]

Yeah what Bob said, just pull the secondaries, sounds better, less heat.. I did throw codes but I have sims in so who cares, it doesn't smell, and passes the sniff test... What I'll probably do with the 08 is pull both cats and then put a random in for optimum flow...

 

[2002_Viper_GTS_ACR]

oh, so codes DO get thrown if you replace JUST the back 2 cats? Damn..

 

[mike & juli]

If you are just planning to eliminate the secondary cats do just that - no need to replace them with different cats. I assume you'll have the primary pair of cats in place so no need to worry about throwing any codes, etc. You will notice a lot cooler cockpit and save money to boot.

What Bob said--we did also. Don't have to worry about providing any replacements or throwing a code. Corsa system sounds totally AWEsome, and we absolutely love the sound and the way the pipes fit on the sides, not extending outwards and 'tacked' so they won't move. ENJOY!! ~juli~

 

[viperbob]

You should not get any codes by only removing the secondary cats.

 

[mike & juli]

oh, so codes DO get thrown if you replace JUST the back 2 cats? Damn..

No, what Bob and I both said--you still have the front cats....no codes thrown, no worries.
~juli~

 

[ILLSMOQ]

there is something else wrong with your car if all you did was pull the secondary cats.

the sensors are before and after the primary cats.....there is only the muffler and pipe behind the secondary cats.

 

[MikeR]

I replaced secondary cats with RT hi-flows. Thought Id get more power and sound. Really didnt notice anything at all. Maybe slightly cooler. Meanwhile my buddy had no cats and I was jealous of his sound.

So I pulled all four cats. Much cooler, a nice mean bark when on it, definately louder and nice power increase, which was noted on dyno. I did not use 02 sims. My buddy had probs with his. So we both have our secondary 02's zip tied under car and have not set any codes. With his sims, he was having trouble, couldnt get into reverse. I would recomend removing cats and zip tie method. Sounded like a cheap ghetto rig idea, but it works with NO problems.

 

[Sleekride]

Shandon,

"The secondaries are a metal substrate cat and the primaries are ceramic"(quoted from a previous post by ?????).

 

[DMan]

FWIW, we have nearly the same setup & if I decided if, more like when, I want to delete the secondaries I'll just do that. I was going to do the 2.5" RTs but .. I found a used - new set for $350, plus local guys wanted $300 to install (although I did the Corsa, I don't think I want to tackle the cats). Just cutting the cats out gives about same power increase (3-6hp) and most folks think it sounds better & it has to cost less than $650 to just have those cut out bya good exhaust shop.

 

[Viper Specialty]

Shandon,

"The secondaries are a metal substrate cat and the primaries are ceramic"(quoted from a previous post by ?????).

That would have been me...


PS- If any of you guys who cut off the secondaries are looking to sell/dump them, let me know. They are worth a few bucks to me...

 

[Paul Hawker]

Often cars will easily pass smog sniffer just after removing secondary cats, but after a couple years you will need the secondary cat to pass smog.

 

[Nsane1]

Dunno what to tell ya, it threw a "no cat present" code, no check engine light. I didn't change anything else, just pulled the secondaries... Like I said, it passes sniff, just threw that code. I bought the sims for the second o2s, code went away... This was 3 years ago, so I never thought much about it. Maybe I'm just lucky, or maybe I had it checked out too soon after I pulled em who knows, it was easily fixed, cheap, and sounds good.

 

[604SRT10]

How many cats is there per side??? Is it not 2??? I bought the Mopar cat back system and thinking about taking one of the cats out, reading all the posts I take it I should have no problems ie check engine lights etc..I was thinking about putting a straight pipe in place of the cat, does anyone know if it is all flanged and clamped or welded...hope it will sound good but really hope it will cool down the cabin!!!!

 

[Viper Specialty]

Dunno what to tell ya, it threw a "no cat present" code, no check engine light. I didn't change anything else, just pulled the secondaries... Like I said, it passes sniff, just threw that code. I bought the sims for the second o2s, code went away... This was 3 years ago, so I never thought much about it. Maybe I'm just lucky, or maybe I had it checked out too soon after I pulled em who knows, it was easily fixed, cheap, and sounds good.

Very odd... the secondaries should have NO effect on the secondary O2's. Probably just coincidence, you may have had a failing primary or O2 sensor.

 

[Viper Specialty]

How many cats is there per side??? Is it not 2??? I bought the Mopar cat back system and thinking about taking one of the cats out, reading all the posts I take it I should have no problems ie check engine lights etc..I was thinking about putting a straight pipe in place of the cat, does anyone know if it is all flanged and clamped or welded...hope it will sound good but really hope it will cool down the cabin!!!!

2 cats per side. Mopar race system replaces ALL FOUR.

 

[Hiss]

I had the secondary removed. Really like the sound & no codes. Now ive got the itch to take out the primary.

 

[604SRT10]

I have the Mopar Cat Back System so it still leaves behind the cats, but I'm thinking about pulling out the secondary cat to keep the interior cooler and hopefully give it better sound

 

[Racer Robbie]

Dunno what to tell ya, it threw a "no cat present" code, no check engine light. I didn't change anything else, just pulled the secondaries... Like I said, it passes sniff, just threw that code. I bought the sims for the second o2s, code went away... This was 3 years ago, so I never thought much about it. Maybe I'm just lucky, or maybe I had it checked out too soon after I pulled em who knows, it was easily fixed, cheap, and sounds good.

The RT cats have the threaded **** welded in place to except the stock O2 sensors so you will not throw a code.

Robbie

 

[Racer Robbie]

I am going to take my 2003 through emissions here in CT this week so we will see if it passes with the RT cats in place that eliminate the secondary cats. Both Jon , at Parts Rack, and RT insured me it would. I also have the 170 thermostat and the DC tune installed. I am going to try running it through as is and will let everyone know what happens.

Robbie