Question about removing cats.

[Explorer96xlt]

I would like to remove my two front cats, but i was just wondering really how much back pressure I am gonna lose. We tow a 5500 lb. boat (give or take 200 lbs.) So i am wondering if my truck will struggle pulling the boat. Also, how much will this cost?

Its a '96 5.0 with 120k miles.

 

[MountaineerGreen]

I personally wouldn't remove the front two cats, they have an 02 sensor after them and your computer will throw codes.

You can remove your secondary cats with no ill effect, I did a long time ago, but I don't know if that will make much difference for towing.

I tow a ~5000 lb camper several times a year with mine. It does pretty good, just don't expect race car starts and make sure your braking system is in good shape. Always tow with the OD off too.

 

[Dignan]

I don't think back pressure will be an issue. I ran my 4.0 without a cat for a couple of years, until I started working at a court and thought about that fine everyday if I got caught. I also had 2.5" exhaust behind the headers. I never had back pressure problems and had a very nice increase in power, acceleration, gas mileage, and sound. For towing, it would help more than hurt for sure. The only two downsides to removing them are: its illegal and the o2 sensors throwing codes as mountaineergree mentioned above.

 

[Dignan]

Oh, I just re-read your post. You also asked how much it costs. If you decide to do it, you can try to find a shop that will weld in a short piece of pipe which would be easy, but none of them like to do it because it is illegal (huge fine, shop gets shut down, etc.) or you can just disconnect the pipes and get a long screwdriver or a rod of some sort and jam it in there and brake up all of the honey-comb-type-stuff in there and empty it out, then re-attach the pipes. So, if you do it yourself like that, it will be free.

 

[Explorer96xlt]

alright, well i guess i will just take the back two out, do the back two have any 02 sensors?

 

[Turdle]

alright, well i guess i will just take the back two out, do the back two have any 02 sensors?

No, the downstream 02 sensors monitor the front cats only.
You don't need to remove the cats, just take them down--jam a piece of re-bar in there and bust up the honeycomb until you can shake it all out, then reattach 'em.

Free mod!!

 

[tktrain]

You can get MIL eliminators that will fool the PCM Computer into thinking that the front cats are there and doing just fine. The are available from most of the Mustang performance parts places and will splice into the secondary O2 sensor wiring.