Hey guys, back from the dead again, haha.

This question deals with my f-150..

It has 140,000ish miles, K&N air intake and a si-do Borla muffler.

Right now its in the process of a 6" Fabtech lift, new balljoints, TCI trans pan, PML polished diff cover, and a few other things i can think of at the moment. I want to upgrade the exhaust since its getting all these other nice pretty toys. I want something thats going to sound like it has a built motor, pissed off, etc.

My son too had a borla muffler on his 01 4.0 SOHC ranger, sounded OK you could tell it was a v-6. Then, he removed the last 2 (of 4) cats and added a si-do flowmaster delta 40 series muffler. It now sounds like a 5.0L mustang. At idle it almost sounds like it has a aftermarket cam, but you have to listen very closely. It never threw a code either.

So on my truck, im wanting to add a flowmaster 40 series and remove 2 of the 4 cats as well. My question is, which cats do i remove? I have read posts on here that say take off the front pre-cats (cats closests to the manifold), or posts that say cut off the rear cats (closest to the tailpipe).

(The removal of the cats would result in a pipe welded in their place)

Oh last question, anyone had any experience with the ebay exhaust kits? They are a heck of a price with the muffler/tips and are 2.5". http://cgi.ebay.com/ebaymotors/ford-...QQcmdZViewItem

Thanks guys.

 

to answer your question, you would want to remove the two rear cats (closest to the tailpipe) Also, since the rear cats also have 02 sensors you will need a mil eliminator, otherwise the truck will throw a code. I am 99% sure this is the correct info, and I am sure there will be others that will throw some info in too!!

 

Sounds good, where do you get the mil eliminators? Is that what most everyone on here is running? Anyone know exactly how they work?

I know im going to have to invest in a programmer, can that take care of the code instead of mil eliminators?

Thanks, i appreciate it!

 

actually quite a few people have gotten by without sims after removing the rear cats. they say the front do an alright job by themselves, or at least well enough not to throw a code.

 

Interesting, i'll just have the last 2 cats removed and see what happens then, thanks!