I had my factory exhaust completely butchered off as soon as I got it 2 years ago. I had a 40 flowmaster put on with a turndown. That was a big mistake.Ever since it has had a lil miss and had gotten worse. So now I'm in the process of putting a catalytic converter back on there but now I have another problem, how many sensors were there on this exhaust because everything was chopped from the cat back. Do I need those sensor sections before I take it back to the exhaust shop.

 

So long as you still have the upstream sensors in the y-pipe, you only have one behind the catalytic converter.

 

So I will need the sensor section that goes behind the converter?

 

Yes, you will need a post-cat HO2S, and that's why it hasn't ran right since you did the install.....the PCM wants that cat data. Also if you install the cat and the HO2S you can leave the Flowmaster on...that's how mine is set up and I have no driveability concerns what-so-ever

 

Thanks for all the info. Tomorrow, Im going to the salvage yard for the sensor section and have to put back on when I have the cat put on. Hopefully, this will be the end of the sh@t!