2 on the rear manifold where the downpipe meets the manifold and 2 under the car just after the cat.

 

So does the ZZP downpipe come with new gaskets or is that seperate bu? Also would I need an O2 Bung extenison?

 

Should come with new gaskets. The extension harness I'm not sure about because I'm no longer using a rear o2 sensor.

If you put a aftermarket downpipe with high flow cat it will throw a engine light for rear o2 unless you have that code tuned out of your pcm just so your aware of this.

 

Yes im aware that the SES light will come on but I can easil get that code deleted. I just dont want to get my old pipe off and not be able to complete the new one because I dont have every necessary part to go with it

 

If your getting the code deleted from the pcm you don't even need the rear o2 hooked up then.

 

The Pipe comes with O2 Bung to place it so I dont want an open hole in it

 

Also I see that people who remove the O2 sensor get worse MPG. Would this still happen if I delete the code? Or would it be better to leave the O2 sensor

 

What do you guys recomend the 2.5" with cat or 3". My car is supercharged but I dont plan on doing many more engine mods to it

 

If you don't plan on going crazy, a 2.5 will be fine for you. Your MPGs shouldn't change, unless your right foot does

 

Well if I were to just add the downpipe will the 3" perform better or worse? Just want to get the best option for my vehicle. So Pros and Cons to each?