So I beleive my cat is broken becuase when i turned on my car, i heard like a little rattling, so its either i have a bad 80 series flowmaser muffler or a bad cat. So i think its the cat, but anyways what is the best cat for your money. I was looking into the magnaflow cats but are those any good??thanks!

and is it possible for my flowmaster 80 series to have gone bad, i bought it on cragslist and has been welded on...thanks again.

 

Ive had good luck with catco

 

do you have a link to one online???and does the cat really affect my performance?

 

they have high flow cats, you can search summit racing for the specs you are looking for. I installed a 3" in and out with a flow master 50 on my 92 silverado several years back. still passes smog. If there is too much back pressure it will effect performance. much lighter than the stock junk so its a weight saving as well.

 

http://www.catcoglobal.com/

I used a universal fit, they may have a direct fit if you are using a air pump.

 

Ima check outthe catco thanks!



and........im willing spend about $100 on the cat but which would be the best high flow cat for my z28?

 

If you go with a bullet type cat, you can select the cell count. Lowest is 100, up to 400

 

Since you're in CA, you need to install a CARB certified converter. I've had very good luck with Magnaflow direct fit converters.

It's not in the scope of your question, but I've installed two of them on my old vehicles that wouldn't pass emission testing (high NOx) and it brought down both NOx and HC numbers to almost nothing.

Go to Magnaflow's web site and grab the P/N for a direct fit CA certified converter. Then head over to ebay and search the P/N. You'll save a bunch of cash doing it this way.

 

^word,my 90 sierra was at 724 for hc's and i had the bullet type cat on it then bought a magnaflow for 64 bucks off summit brought way down to 220 which is the nj limit also adjusted timing alittle but still played a big part.I still have the sheet in front of me.

 

Catco has a direct fit model ct-9118 that is a 3" in/out hi-flow. Also CARB certified.

 

Before you go through all the trouble of replacing a cat be sure its the problem. I used a mechanics stethoscope but a hose will work. Lightly place one end of the hose on the cat and the other on your ear and listen for the rattle. Also the heat shields above the cat mounted to the floor panel can start to rattle little. You can take a ball of aluminum foil and place it between the shields to see if that stops the noise.
I run a Magnaflow cat and as stated above it also helped me pass a smog test here in CA. They have a very good reputation of being extremely well built.
Here's a list of Magnaflow cats that you can use as a replacement,you just need to find out what size inlet and outlet you want.
http://www.summitracing.com/search/Y...?Ns=Rank%7cAsc
On my 89 Camaro the stock cat was 2.250 inlet and 2.500 outlet .
By the way the cat has to look like the stock cat for the visual inspection here in CA. . I don't beleave a bullet cat does that.
Myself and a installer had to fill out paper work (a converter warranty certificate/installation statement) to show to any smog shop that ask for it stating that the stock cat was damaged in order to have it replaced.This means you cant replace it yourself you must take it into a shop that uses this paperwork.

By ronusmcmma at 2012-05-06