I have an 80 series muffler on there but need to go for inspection soon, so I need a cat. I'm looking for a high flow cat, good choice? I will looking into pacesetters or magnaflow. What do you think I should go with? Thanks guys

 

any new catco cat, or any stock cat off any newer car should suit you fine.

i bet you could get a 98+ cavilier cat (or somthing) from the wreckers cheap, and they are high flow enough

 

Basically any new aftermarket catalytic covertor now days is a "highflow" unit. They are better made no using better flowing inerts then the '80's units the cars originally came with.

Make sure you buy a 3-way convertor and not a 2way. Our cars emissions levels require an ORC cat wihich is a 3way meaning it converts the levels of NOx also which is part of a smog check for our years.
http://www.car-sound.com/04converter.asp

 

I just purchased a Magnaflow DIRECT FIT for my 1985 Ride
It's a 2 WAY item, not a Three Way type.
My 1985 Blazer is also a TWO way CC.
Check before ya need buy what specific type you do need. Sounds like it varies from year to year or drivetrain set up.
I paid $113 including shipping. From Summit.
I hope to tell ya later on "how direct fit" it really is!
I am hoping for an unbolt, twist, remove old, slip on new, tighten clamp type installtion.
What I really hope for is finding a CC rebuildier of my old AC Delco CC shell so I may have it used on my 1985 Blazer when that CC fails or wears out.
My personal application calls for part number 23494 Magnaflow. 2 1/2" in & 2 1/2" out. I am using a F body 3.4 part, for it's larger size. The pipes on my 1985 car, seeming original, this part fits. YET the magnaflow parts list says my "original" should actually be slightly smaller in size. Oh well!

 

Karl, get ready to see your NOx go throuh the roof if you really just got a 2-way CAT.

2-ways are known as OC, or Oxidizing catalysts, and ONLY have Platinum and Palladium in them. All they do is Oxidize HC and CO, nothing for NOx.

3-Way cats, aka "ORC"(Oxidizing/Reducing Catalyst), as RTFC said, do all 3 gases. They have 2 seperate beds in them, the fromnt bed is coated with Rhodium to Reduce the wmount of NOx in the exhaust, and the rear bed is coated with Platinum and Palladium, to Oxidize the HC and CO.

DO NOT BUY CATCO, they are cheap for a reason. when you buy a cat for $99, it has very little coating on the substrate and does the job for only about 6 months, the next time you come up for inspection, you'll need a new one. Now, this doesn't always apply, I have heard from a few people, like TomP, that they last forever, those are the lucky ones. In my experience, when a car comes into the shop with a CATCO cat that was put on the inspection 2 years before, it has a hell of a time passing emissions.

I say stick with Magnaflow, Carsound and the like. They are more expensive right off the bat, but last a lot longer.

 

I just installed the Magnaflow Direct fit and gotta say...
it IS A DIRECT FIT!

Also changed my oxy sensor.
NOW on the 2 way, 3 way debate.
That's what's stock for this 1985 car. Two way CC.
AS long as it passes smog, don't truly care, all I know is it is correct item for my ride.
There NEVER WAS a 3 way set up on this 1985 ride.
Nor is their a 3 way set up on my 1985 S-10 Blazer.
I do know the difference. I did not buy a 2 way CC for being cheap.
That's all I truly needed for my car.
We'll know the smog results soon enough!
Be seeing you shortly!

 

Thanks guys, what about pacesetters? Are theres any good. I will prob have to weld in my cat where it connects to the Y pipe I think, but other than that it should be fine

 

Pace Setter Exhaust does not offer a cat convertor for our rides.
Summit was cheapest price of direct fit with their price of Magnaforce.
I priced out all direct fit options, too.
Universal cat convertors go for less, but the labor is more intense. YET if your cars pipes are hacked up, Universal fit is a wise option, too.

 

So you would go with magna flow direct fit? They carry a universal right? I have to look it up sometime soon I wonder how much of a fine it is in MA to be caught without a cat My car is also running a bit rich, will this kill the cat? It gets about 20 mpg now though. Just smells it and has a rough idle at first when I start it. Worried it may kill the cat? Thanks again

 

I think running rich in the AM killed mine. I hope by changing the oxy sensor, my AM rich running problem is now gone.
I wouldn't suggest any product.
All I am saying is that of the direct fits I was seeking Magnaflow & Summit selling them were the best deal out there.
Universal fits with summit prices were in the $80 range.
The price I paid INCLUDED shipping AND handling.
My car pipes are in great shape so everything went well on my install. We only needed to bang on the damn CC & twist/wiggle, while I pushed it off from other end.
Yes I am in rust free California.
Yes I do feel for you others in the other states with rust problems, because I used to live there, too.
Haven't a clue what MASS Staties would do to you about your lack of a CC.

 

If you are truly running rich, the cat will die in a hurry.

I Suggest replacing the O2 while you're at it, just makes good sense and helps the new CAT work better.

The current CAT is probably just bad, when mine was bad, it smelled REALLY fat all the time, but as soon as I installed a new one, the smell went away. Man, it was strong too, you could smell it everytime I came to a stop. Made me feel sick on more than 1 occasion.

Don't worry too much about running rich in the morning when the car is dead cold. What actually kills the convertor is the unburnt HC going into it when the CAT is 600*F. The HC litterally catch fire and burn up the CAT, in the most litteral sense of the word. When the car is cold, it runs a little rich and more HC than normal go down there, but the convertor is cold too, so they just pass right out the tailpipe with no damage.