okay i got an 02 f-250 superduty with the 5.4 auto and im wanting a louder crackling exhaust and iv been told that the cats on these trucks are resticive and really quite the sound and ive been thinking about putting are magnaflow spun metallic cat on it but i dunno if that will be any better there is no 02 sensor behind the cat so im not too wondered about that or should i still be? any ideas on how to get a nice crackle when i get on it? thanks for any ideas

 

Ok, I suppose I should tell you the truth about spun cats (this applies to all brands). Spun cats achieve their higher flow ratings by reducing the cell density, which reduces the catalyst efficiency. In addition, the metal substrate has far less surface area than ceramic, which reduces the efficiency even further. As the catalyst degrades, the surface area becomes less effective. This is a conceptual problem with metallics, and applies to all manufacturers, regardless of the process used to make them.

The OEM catalyst is restrictive because it is so large. It causes the exhaust to expand and cool (even though the catalyst reaction produces heat). This muffles the sound and kills some performance. The cat I have used on many of these and have seen very good results in both sound and performance is this

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This cat is properly sized for the vehicle, and allows much more sound to pass through and will be just as loud as anything else on the market. It also costs much less than a metallic cat. The size comparison isn't even close, the Magnaflow spun metal cats are only good on vehicles up to 6,000 lbs. Your F-250 is a lot more than that, it should be at least 8,600 lbs. The cat I am recommending is good on vehicles up to 10,000 lbs and on engines up to 7.5L.

 

Would changing the y pipe and the cat make it too loud to pass NJ inspections? I have a super 44 with dual outlets and long tips and I would love more sound but I wouldn't like it to be extreme enough to get pulled over.

 

im glad i dont hav kinda problem here the only thing i have to worry is about some of the cops in some local towns will pull u over if ur to loud bit its like a 75 dollor fine i dont have have emisions test for now atleast but i see that getting changed before to long

 

I cannot speak for your local noise laws, but it should still be reasonably mild with our cat, not ear splitting loud or anything. It would be somewhat louder than stock, but much quieter than straight pipes or glasspacks. With the muffler you have, it shouldn't be too bad.

 

I have a Dynatech cat (similar to the magnaflow spun) on my 04' 6.8l SD. Emissions don't matter for me, I just have to have a cat on the truck for visual purposes to pass inspection.

What does wake up the exhaust note below 3k rpm is the Ebay y-pipe that replaces the restrctive section of the stock y-pipe. I put one on my dads V10 SD for him and it really made it louder. Now he wants me to put on a quieter muffler. (He currently has an FM50 SUV muffler with a lightning style exhaust)

Neither my 04' or my dads 03' has a rear O2 sensor. The 5.4l and the 6.8l in the SDs use the same Y-pipe.