Alrighty I just removed my cat and welded in the new pipe this morning. Put my non fouler in with the old o2 sensor and all seems good. Here's my question. Since the front o2 sensor isn't in use anymore, would replacing the rear o2 sensor help with fuel economy and idle and what have you or is that as good as it's gonna get? I don't think the back one contributes much of anything if I'm not mistaken. On a side note, if I was pissing off neighbors before with my exhaust I'm causing some real hate and discontent now Next is headers to make my exhaust complete.

 

Why is the front 02 sensor not in use anymore? Did you remove it?

The front o2 is what controls the engine - Fuel levels, keeping the engine running efficiently, etc. Replacing this one, if it's causing an issue, should help with the mpg's, but that depends on the problems being experienced.
The rear o2 is the one that should not be in use anymore. It should be getting fooled into seeing a false oxygen level change that would simulate the cat. All the rear o2 does it monitor catalytic efficiency. Thats it.
Just making sure you have your info right.

 

Your right I mis interpreted. I put the non fouler in the rear one after the cat. Not sure what I was thinking.

 

so if i punch out my cat and put in two spark plug non foulers i wont have any engine codes?
just tryin to make sure cause my cat is rattling alot and i hate hearing that noise while at a stop sign

 

You only have to do it to the second sensor after the cat. I just drilled a hole into the new piece of pipe and put my old sensor in it and I don't have any codes. I was just wondering if I replace the front sensor with a new one would it make a difference as my cat is no longer there.

 

Nope. The front sensor has nothing to do with the converter.

I recommend NGK sensors if you can find them, but Bosch can work as well.

 

I hollowed my cat out and now my truck don't seem to be running right, what could it be

 

Need more info, gonehuntin, what is your truck doing now? What was it doing before you hollowed that cat?

 

if you hammered and banged without first removing the O2 sensors you may have damaged them.

if that's the ONLY thing you've done since it was last running right, then i'd replace front O2, and reset pcm.

 

I was actually planning on getting my cat cut off tomorrow. I have a 2000 and was wondering if I had to do the non fouler trick, or can I just get the cat cut off and be fine. If it just throws a code thats fine but I don't want to be running rough and getting bad economy afterwards.