My car currently has a half-assed 3" MP that I want to put a cat in so I can pass emmissions. I want to get a 3" high flow magnaflow cat for it, but I'm not sure whether a round or an oval shaped cat will work the best. Can anyone give me some input?

 

I bought an N-tech hi-flow for $340.00 brand new. The new cat flows really well and WILL pass emissions here in CA.

I ran the car for about a month without the airpump hooked up. The car stunk and wouldn't idle smoothly. So you DO need the airpump connected, contrary to what they say at N-tech.

I definitly felt an increase in power of the stock cat. I also took the car to a local gas station to do a "sniff test". I made sure that the mechanic didn't send any info to DMV, just in case i didn't pass. The mechanic said the car's exhaust emissions were very clean and should pass without any problems. But passing the visual is another story...he didn't like the looks of my monster ASP RACE SMIC and custome CAI.

The hi-flow cat and the dp would pass the visual test...

 

Is that $340 for just the cat? Or is it a catted midpipe? What are the dimensions of the cat? I can get a 3" magnaflow for $129, I'm just not sure if it will fit. Thanks for the advice.

 

Could someone just give me the dimensions of the stock cat?

 

The oval shaped cat will work better I think, I don't have the dimensions of the stock cat here but I know from memory the thing is a huge brick. I didn't know Magnaflow even made a round cat, but I would be worried that the dimensions may be too large and hit the underside of the car when mounted. An oval cat gives you a flatter area similar to the stock unit. FWIW I bought a 3" Catco HF cat from Summit for $50 that I am going to hollow out and weld onto my midpipe.

 

Thanks a lot for the help. What are the dimensions of the catco?

 

Toddzilla,

If you remove the upper and lower external shields of the stock cat by unbolting them, you are left with an odd-shaped converter section which includes a crimped-on shield that cannot be removed. Measuring that shield, there is a rectangular center section 10 3/4" long by 8 3/4" wide by 5" deep. Then there are tapered portions (still part of the same piece) which add 4 1/2" toward the front, tapering down to the angled pipe, and another 2 3/4" to the rear. I don't know how much of what I measured is actually converter and how much is just shielding.

FWIW, with a Bonez cat (which has no bolt-on external shields), replacing the stock cat, and a Bonez dp replacing the pre-cat, the passenger compartment is warmer, not cooler. My car did not pass CA emissions in that configuration, but a new stock cat did pass using the Bonez dp, and the passenger compartment is back to its previous temperature.

---- Bill

 

Well from memory again here since the cat is at home in the garage; I know it is 14" long, about 7" wide, and 3.5" deep. If you go to summitracing.com and look under the Catco converters it is the 14" SS 3" inlet/outlet version.

Matt