So, is it worth the $$? Yes, I know I have a 305 TBI. Future plans for the car include an open element air cleaner, Vortec heads and an LT1 or aftermarket cam, and either the higher-flowing TPI manifolds or headers. I think I may need a cat anyways, as my NOx fails for an inspection sticker...

Any thoughts? Should I just go with one high-flow cat? I supposedly have a high-flow Magnaflow on it right now that is only 3-4 years old, but as I said my NOx is high. The car sat a lot (driven 3k in 4 years), and I have a feeling old/bad gas may have messed up the cat.

Any help is appreciated...

 

i think i have dual cat magnaflows on mine, the previous owner spent 1700 dollars on it, with headers and everything. Sounds really darn good

 

am I missing something? that picture looks like a 2in / 2out muffler, not a catalytic converter.... Your catalytic converters should be behind your RF tire under the passenger side floorpan.

If you do have a dual-cat exhaust system (2 catalytic converters in the location I described above) then I'd stick with that and get a less restrictive muffler welded in place. If not, I'd get a 3" catback setup from Flowmaster or whoever and replace the catalytic converter with a high flow model.

Dark_daku89, I'd really like to see more pics of the rest of your exhaust if possible. It looks like you have dual exhaust, with one pipe going over each side of your rear axle. Any more pics would be appreciated. Thanks!

 

yeah thats the only pic i have of my exhaust. I have to check if i have cats where u described. I have no idea what the previous owner put on, but once i get my car up on a hoist, ill have a look and then get back to u.

sry about the mix up, i wasnt sure that u wanted to see the cats, but like i said thats the only pic of my exhaust, for now anyways.

 

i just checked and it looks like i dont have ne cats. I guess its not a law over here in winnipeg, mb canada

 

dark_daku89 , you HAVE to post more pix of that exhaust setup. It really does look like you have a true dual from what I can see. You have an idea (can you measure) of the diameter of the intermediate pipes...and while your at it snap some more pix. if the previous owner was telling you 1700 bux canadian (that's like 126 USD right) <-that was joke. Then the previous owner may have sprung for a true dual fabrication. Anyway....I'd be *along with may others* interested in any other info you can provide on your exhaust setup. Thanks in advance.

 

I've always thought it would be nice to send a 2nd pipe over the other side of the axle, provided it was high enough and you put some sorta heat shield around it to prevent the fuel tank from getting too hot (boom).

Looks like you've got a nice setup there. Please, more pics when you get the chance, I mean I'd like to have a nice high res. pic every foot or two from the underneath of the car, if possible.

Getting back on topic, Jason E, if you don't see any cats where I described, that could be the reason for your excessive NOX emissions or CO2 emissions or whatever you might be getting.

BTW 1700 CDN is like 1400 or 1500 US.

 

1528

 

I finally managed to get some pics online, I dunno if there is a set limit on how many pics u can have on so sry if i put too many.

(ps) I know there is a lot of rust

 

So, uh, can anyone actually answer my question? My thread got a little hijacked here!!

 

Jason, save yourself some money for now and just purchase the hi-flow cat instead. Doesn't look like you even have one right now from what I could see in the pix (thanks by the way). Magnaflow is pretty pricey and I'm not even sure they have a product for our cars anymore. If you really want to replace the cat and cat-back I'd opt for a flowmaster, pacesetter, or Edelbrock (also a bit pricey for what you get). My 2cts

 

Those pics aren't even my car That's the hijacked thread part!!!



Anyway, the car actually did pass for a sticker yesterday. When I bought it the EGR valve was stuck shut, and despite replacing that and doing a full tune up, the emissions were too high. I have a "high flow" Magnaflow cat already on it, and was thinking I might need to replace it because of the emissions (I figured the faulty EGR might have screwed up the cat)...

Well, it passed, so now I have all the time in the world...but I'd still like to know if this is a beneficial mod or not!

 

hey sry about hijacking ur thread!!!

 

Jason, I'm not aware of any "dual-cat" setup by Magnaflow. If you have pictures or a link to this then I'd be glad to take a look at it for you.

I thought that Magnaflow only made mufflers, but if they do make cats, then it's probably just stock replacements for the few TPI350 cars which came with this special y-pipe from the factory.

If you have a dual-cat setup on your car (very unlikely on a '91 RS) then you could replace the cats with high-flow magnaflow cats and it will be less restrictive on the exhaust side, depending on how clogged your current cats are. If you don't have this dual-cat setup on your car, then I'd suggest you get a 3" cat-back exhaust system and a good 3" high-flow cat to replace your stock one (if it's even still there).

If Magnaflow sells a dual-cat setup which includes the y-pipe and all, then that'd probably be worth it too. I'd probably be looking for some shorty headers to install at the same time, however, if you're already gonna have it in a shop.

If you're talking about a magnaflow cat-back exhaust system, then that would be worth it as well. This would include the pipes that bolt / weld to the cat all the way back to the tips coming out the back of your car. Again, I'd suggest replacing the cat at the same time if you plan on doing any work to your exhaust. Most likely, the failed EGR has clogged it all to crap and it is probably quite a restriction. Hope this helps.

 

Here is the link to it...

MagnaFlow Direct-Fit Catalytic Converters: MPE-23479 - summitracing.com

That's what I want to add...will it work? Do I need a new Y pipe? I've been thinking about doing the Edlebrock TES anyway, which I believe includes a new Y pipe anyway? Help!

 

ya taht's the whole y-pipe and catalytic converters. I bet your car only has 1 on there right now. what i'd do is get the shorty headers that hooker makes (I have the Edelbrock TES, I've heard much better about the hooker ones) and the y-pipe as well. If you can afford it and plan on keeping the same exhaust setup, get them jet-coated. Then you'll need a single 3" high-flow catalytic converter, and a 3" catback exhaust. That exhaust should eliminate any exhaust restrictions until your motor has you in the 12s.

Don't just take my word though, do some research and have a look on here to see what other people are running for exhaust. my $.02