my 2007 f-150 5.4l currently has a magnaflow system on it (p#16616) and was looking to make it a little louder. I was thinkin that i should install two magnaflow hi flows P#94106 in place of the two stock cats. My question is do i need o2 extensions and where do i get them ive looked on ebay and have had no luck? Cheers joel

 

Only time you need extensions is if you install long tube headers

 

ok sweet does anyone know how much louder these will be compared to the stock cats?

 

I have those Cat's. I bought relocating kits for my O2's just make sure you put them after the cat's to avoid cel. They definatly are louder.

 

I would think it would sound similar to removing the rear cats, Darren has before & after videos of his cat project. I've removed mine, and it does make it a lot louder.

 

I have been looking into replacing my 2 stock cats with high flow cats as well but wasn't sure it would be worth it.

How much louder would it be?
Will it void my warranty?
How much should it cost?
Would I need to do anything else in tandem with the new cats?

Thanks.

 

It will be louder, at least 30 - 45% louder with the 94106s.
It will void your exhaust warranty only.
$67 per cat from Performance Curve, $100 - $200 installed
Just make sure the rear sensors are mounted after the new cats.

 

Wow. Thanks Darren. I didn't realize that high flows would do that much. This is definitely a job that I should leave to an exhaust expert then?

 

And they flow better, increasing economy modest and more performance under WOT.

 

Also keep the stock cats and sell them to a shop or recycling yard, they are worth nothing as cats but the material inside is platinum and worth a lot of money

 

yessir. i have them (94106's) and love em. louder, sound better, and help flow. what more does anyone want? lol $200 installed for me.

 

Hey did you need o2 extesions?

After the cats mean closer to the heads up or after the cat facing down?

 

After, as in behind the cats going towards the back.

 

Thanks for clearing that up for me.