does my 4.6 have to have all 4 converters on it? my truck is striaght piped other than the 4 converters and would like it to be loader.

 

remove all 4 cats and install 2 high flow cats and you'll be alot louder and still smog legal

 

we dont have to have any inspections here in arkansas. can i just remove the back two and it still run right?

 

if you remove the front 2 then yes and it'll be louder

 

Which two have the 02 sensors?

 

GM trucks have them in the cats, his '98 has the o2 sensors just after the rear cats

the fronts can be remopved without issues

 

5 & 6 = Upstream Oxygen sensors.

3 & 8 = Down stream Oxygen sensors.


I ran this set up w/Flowmaster 50 series muffler with stock tune for awhile. You'll want some kind of muffler on there with the stock tune, unless you absolutely don't care about torque or performance. Throw a at-least a 40 on their. Torque gonna take a hit know matter what, but it won't be as bad with something at the end.

Here's the set up I ran with a 50 - Favorite sounding set-up I've run to date. The 5four sounded like an old Mustang GT under normal acceleration. Muffler not shown / Rear cats illuminated / within parameters (No CEL) -

 

A few years later, I went with this -





Sounded like this -

First start -

http://picasaweb.google.com/jbrew393...47495635595234

First time out -

http://picasaweb.google.com/jbrew393...40433327124514

 

So removing the front two wont throw and error codes? Will it still pass inspection?

 

Doesn't matter, either or. Front two are pre-cats. If you want to off the pre cats , you really don't need to do any cutting/welding/bending. An auger bit and drill motor will gut them without pipe modification. - Just drop the exhaust down in front and gut them. Then bolt her back up - done.

Yea , - no CELS - I removed the rears tho and left the front (pre cats) alone. The rears have more material inside.

Nowadays , it worth it just to off them all and replace with high flows. Salvage yard gave me $160 for my stock cats when I did it, but now guys are getting $200 + for their old stockers. A new set of HF's are only about $150. So...