I have an exhaust manifold leak, so I figured might as well get some headers.. Now Im thinking of going 3" for the whole exhaust..but I dont have the money right now to get headers, y pipe, cat, and catback all at once. So can I start by getting the headers and y pipe? At the exhaust/muffler shop they should just be able to weld some pipe to connect the 3" end of the y pipe to the 2.5" stock cat, right? And then just cut it off and weld it again when I get a new cat and catback. Will it make a big difference in cost? Im thinking it shouldnt since its just a tiny bit of extra labor.

I have a 92 rs, 305 tbi.. I have so many things to fix before I even think about making it faster than stock.. So does it even make sense to switch to 3" exhaust? Im still not sure if Im going to put a 350 in the car or just keep it a cruiser and not worry about going fast. I was considering just buying these Edelbrock headers and calling it a day on the exhaust til I fix everything else: http://www.summitracing.com/parts/EDL-68753/

 

if your exhaust is still stock you will have a dual cat and wont be able to weld that y pipe directly up to it, you will have to go to a single cat or lose the cat all together (not sure of your location and emissions)

that y pipe probably only has a 2.5 outlet anyway and you would have to modify it to 3"

if you dont have to worry about emissions you could temperarily weld a bullet style muffler to the end of the y pipe in the cats location but it will be fairly loud and your exhaust will be at your doors

 

If you do it piece by piece and you have a shop do the work for you, you're looking at a lot of extra money to keep having them cut and weld sections in. Depending on where the leak is it might be better to fix the leak and then save up to do the whole system at once. Or just live with the leak for bit until you can save up to do it all at once. Just my .02

 

if your going to swap the 305 for a 350 then I would wait to swap the engine then get the full 3" header exhaust. Or I would keep the 305 and get 3" headers + exhaust now and save the 350 upgrade for down the road a year or two.

 

thanks for the advice

It has dual exhaust but I think it's not true dual, it only has 1 cat. I'm pretty sure it's stock. Are you sure stock exhaust came with dual cats? In a 305 tbi, 92 RS?

the ypipe is 2.5.. I was just thinking of putting on there and sticking with 2.5" until I get a 350. I heard it won't make a big difference anyway with the 305.

I'm in CA and I want to follow the emissions laws.

 

as far as i know they were all dual cat from 1990 on, i know my 1991 has them. easiest way to know would be check under the car behind the front passenger wheel and check. being in CA makes things a bit more difficult for you. and if you do have dual cats i believe the only ypipe offered is from dyno don and it is a pricey set up.

i dont know CA laws as far as switching from dual cat to a single highflow cat but that could be an option

 

In CA if it came stock with two cats than that's what the visual smog inspection will be looking for.

 

where in California are you?

 

The smog test papers say Exhaust: Single.. and all the other information is correct. It has two tailpipes but I think it's just that, two tailpipes but not true dual. I'll check tomorrow. I'm pretty sure I only remember seeing one catalytic converter though.

I'm in Northern California. Why?

 

my 92 rs with 305 tbi only had one cat . yes you can add in pieces .
these are the ones i have . 2 1/2" ypipe :
http://www.ebay.com/itm/NEW-SHORTY-H...sories&vxp=mtr

 

Because if you were Orange County I could send you to Dyno Don and he could fix up with good exhaust system. No big deal.

 

Dual Cats are from 89-92(G92 pacage). Keep the dual cats and run a flowmaster y-pipe adapter after the cats. Get the one with dual 2 1/2in-3in out. Then use any 3in cat back system. Keep it simple. Remember theres a y-pipe before the single cat and there is a y-pipe after the dual cats.