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Installing Trans Am catalytic converter and exhaust on a v6


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#1 V6vert

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Posted 15 March 2020 - 02:40 PM

I own a 2000 V6 Firebird convertible. It needs a new catalytic converter. I have also been considering a cat back exhaust system for this car. On craigslist I found a seller with a 1994 Trans Am exhaust system with Flowmaster mufflers. The Trans Am catalytic converter is included with this system.

Will I be able to use the catalytic converter from the Trans Am on my V6? My friend does all labor on my car for free so I dont want to give him a job thats a pain in the butt and requires a lot of modification. If any adapters or extra pieces are needed, Id love to know what they are so i can have everything ready.
I live in NY so I cant get rid of the cat.

Also, will the Trans Am exhaust be an upgrade over my stock exhaust and how will it sound?

Thanks so much in advance.

-Casey

#2 sea dog

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Posted 15 March 2020 - 03:06 PM

I'm afraid the trans am exhaust will be too much for a stock 3.8 v6 car. Keep searching until you find what you need for your car.



#3 V6vert

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Posted 15 March 2020 - 03:16 PM

I'm afraid the trans am exhaust will be too much for a stock 3.8 v6 car. Keep searching until you find what you need for your car.

 

So you're suggesting I get a v6-specific catback because the T/A exhaust won't sound good or perform well? 



#4 Injuneer

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Posted 15 March 2020 - 08:03 PM

No.  It will not fit.

 

The problem is the Y-pipe connections to the exhaust manifolds.  The layout is going to be totally different.  Connections to the V8 manifolds are in different locations than the V6 manifolds.  The 93-95 V8 Y-pipe driver side branch actually goes forward, around the front of the V8 engine, under the oil pan.  Seriously doubt the 3.8L V6 is anything like that.

 

Doesn't NY follow CA rules with respect to emissions?  If so, you are going to need a CA certified cat on the car.

 

Then you mention a V8 catback System with “Flowmaster mufflers”.  All 4th Gens only have a single cross-flow muffler mounted transversely behind the rear axle.  Or are you actually looking at a “true dual” exhaust system for a 94 LT1 V8?  That would involve dual cats, and be total overkill on a V6.  And would not meet Federal emissions, since it is against Federal law to relocate the cat or change the number of cats.  And.... a 94 V8 is OBD-1 and would not have the required bung for your OBD-2 V6 after-cat O2 sensor.


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#5 V6vert

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Posted 16 March 2020 - 03:05 AM

No.  It will not fit.

 

The problem is the Y-pipe connections to the exhaust manifolds.  The layout is going to be totally different.  Connections to the V8 manifolds are in different locations than the V6 manifolds.  The 93-95 V8 Y-pipe driver side branch actually goes forward, around the front of the V8 engine, under the oil pan.  Seriously doubt the 3.8L V6 is anything like that.

 

Doesn't NY follow CA rules with respect to emissions?  If so, you are going to need a CA certified cat on the car.

 

Then you mention a V8 catback System with “Flowmaster mufflers”.  All 4th Gens only have a single cross-flow muffler mounted transversely behind the rear axle.  Or are you actually looking at a “true dual” exhaust system for a 94 LT1 V8?  That would involve dual cats, and be total overkill on a V6.  And would not meet Federal emissions, since it is against Federal law to relocate the cat or change the number of cats.  And.... a 94 V8 is OBD-1 and would not have the required bung for your OBD-2 V6 after-cat O2 sensor.

 

Thanks for your reply.   I'll just get a proper catylitic converter for my car.   Regarding the exhaust, I meant to say "Flowmaster muffler".  Sorry for the confusion.  This is otherwise a stock trans am exhaust.  Would it make any sense to install this on my v6?  Would I see a nice sound improvement or would I just be better off putting in a magnaflow muffler and calling it a day?



#6 Injuneer

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Posted 16 March 2020 - 05:38 AM

Not sure I understand your question..... Are you now asking ONLY about using a 94 Trans Am V8 catback on your 2000?  I don’t know the details of the 94 cat  to intermediate pipe connection on the V6, or exactly where the after-cat O2 sensor is located.  On the V8 models, if you want to mix 93-97 with 98-02, there is an additional “S-pipe” involved.

 

You also need to correct your profile info - it shows the year as “2004”.

 

Sound is subjective. Hopefully some 3.8L V6 owners will respond.  Unfortunately not many of them do respond any more.  If you are looking for a significant performance increase, I don’t think you are going to be able to feel it. 



#7 tom99

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Posted 16 March 2020 - 06:15 PM

T/a exhaust is laid out different.... however you can remove the oe muffler and get a duel outlet muffler and tailpipes from a Trans am, a competent muffler shop can do the whole job for you for, There will be a adapter and fiddling to attach the muffler to your oe extension pipe. If you want a direct fit up Flowmaster offer a complete cat back 17358 for the 3.8 Firebird


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#8 V6vert

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Posted 17 March 2020 - 05:25 AM

Thanks everyone.  Doesn't sound like it's going to work.  With the age of my stock system and 20 years of NY winters I'll probably just go ahead and replace everything from the cat to the tailpipe.  Headers too if the price is right.  This is more than I'd like to spend though.  Any suggestions on finding used systems?  I can't find any.



#9 V6vert

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Posted 19 March 2020 - 05:47 AM

I ended up calling ws6store and they gave me a much better price than the advertised price on a magnaflow direct fit cat and catback exhaust. 

Thanks everyone for your help.






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