Rear Catalytic Converter question

[tbolt1003]

My 95 Impreza 2.2 with 122,000 miles developed an exhaust leak where the rear cat meets the resonator pipe. The flange on the cat section is completely rusted away and the (2) pipes are no longer a tight fit as the bolts have nothing to attach to. The only way to fix it is a new rear cat, which aren't that expensive aftermarket.

 

I've located a few well known brands for between $135-$150 which are direct-fit models and come with both gaskets. There is also a MagnaFlow model for around $200. I think I already know the answer to my question, but will I really gain that much by going with the mandrel-bent MagnaFlow over an OE replacement? I'm guessing "no" but wanted to ask first. Thanks!

[Fairtax4me]

You can get a split repair flange at Napa that fits around the pipe. About $10. Just knock off the rest of the rusted out stuff and the two halves wrap around the pipe just in front of the hump where the flange was welded on. Might need some longer bolts, but they don't need to be the spring type.

 

 

As for the question about magnaflow, those are generally high flow type converters, and won't do much good performance wise on your car. They're usually stainless steel though, which won't ever rust out again. But how long are you really gonna keep the car?

Edited February 22, 2014 by Fairtax4me

[tbolt1003]

That's great news about the split flange kit. Thanks for the info!

 

I figured as much about the MagnaFlow unit. Not worth the added $$$. Thanks for confirming my beliefs. I do plan on hanging onto this car until it starts to nickel and dime me. So far, knock on wood, it's been really good to me. Probably most I've spent on it is a front hub assembly and the (4) snow tires this past November.

[wtdash]

This is a cool fix...didn't know about it.

 

Go from this:

To this:

 

[tbolt1003]

Fairtax, is the size flange kit I need on the converter side an 1-3/4" or a 2"? They offer both sizes. Sorry, i didnt think to get a measurement before heading out to the parts store. Thinking 1-3/4"??

[Fairtax4me]

I don't remember which size that pipe is off the top of my head. I wanna say 1-3/4", but not 100% sure.

Usually the parts store will let you return the one that doesn't fit if you buy both sizes.

 

If you get the type of flange pictured above, you may need to trim part of the heat shield on the cat to get it to fit. There is another type that's made from two sections of bent steel wire about 3/8" diameter. The ends are stamped flat with holes cut out. It doesn't clamp down around the pipe, but it still works well if you get the correct size and have enough of the weld hump left on the pipe.

 

Here's a picture of one: http://m.summitracing.com/parts/wlk-31871

Edited February 22, 2014 by Fairtax4me

[tbolt1003]

Thanks. I'll just get both and return whichever doesn't fit. I googled the repair kit and the one shown above isn't one that pops up commonly for the Subaru repair. The flange kit looks a lot more durable than the factory set-up.

 

Thanks, again, for your help. This forum is definitely friendlier than the other one I am on (will remain nameless). They seem more into helping people with WRX's and STi's than us under-powered guys (I'd love to get a DGM STi someday...). Still a great site, but I'm getting a lot more response and help here. Even added the USMB app to my phone.

 

Thanks again!

[tbolt1003]

$9 worth of parts and 1.5 hours of my time and it's good to go. I had to cut the bolts off, as they were badly rusted on there. Once they were out of the way, smooth sailing. Thanks again for all the help and suggestions.