Garza08

i heard that my truck has 4 catalytic converters and i wanted to remove two of them. the ones towards the back then also replace the stock muffler with a flowmaster but i was told by a shop that i couldnt take off any catalytic converters due to sensors but my dads 2004 5.4 4wd he took the same ones out that i wanna remove and he has had no problems.. any opinions on wat i should do or is there any problems at all really need help.

ProZach

subscribed. I would like to know too. it could be the difference in engines?

techrep

iTrader: (1)

You can plug up some o2 simulators after removal and have no problems

otto457

Do the Gotts O2 mod for the cats and stay away from Flowmasters.

http://www.f150online.com/forums/exh...-mod-pics.html

bossman15

The rear sensors might trip a code but removing them will not affect anything. You could get a programmer as well that turns them off such as a gryphon or sct. And I have all 4 cut off with 2 high flow cats with a sido super 44 and it sounds dirty. Don't listen to all these magnaflow fanboys, we don't drive racecars where performance and sipping up every bit of horsepower is a necessity,if you like the sound get it.

kevhead75

On the 4 cat system I believe the second O2 sensor is between the front and rear cat. Theoretically you should be able to remove the rear cat without throwing a CEL. Although it is a federal offense to remove a functioning cat and alot of shops will not remove them unless they are damaged and being replaced. You should be able to look under the truck and see where the O2's are in relation to the cats.
Kev

05 f150

I have a 2005 XLT with the 4.6 and it only has two catalytic converters in it

Biggbay

I see four parts