exhaust dump

[Aveo_Tuner]

hey guys i could use some help on this one, i have a 2" cat back exhaust with a vibrant muffler on the rear and i get massive amounts of backfire on high rpm down shifts, if i do the mod to remove the cat its going to be pretty obvious that i dont have one right? because of the flames and all. With nothing to stop them how bad do you think it will be? has anyone done this kind of setup on a small displacement engine that can shed some light for me? thx in advance

[y2dgone]

now wait, if the 2nd sensor just wants to know if there is less gunk then wouldnt it not matter if the dump was before, because then either way there is less gunk getting to the 2nd o2

Good point, but I'd like to think it's looking for more detail than just less stuff. I think the only purpose of the 2nd o2 sensor is to make sure the CATs are doing the job.

Well you know what I mean. I'm trying to figure out if the 2nd cat kicks on a CEL only if the PPM is above a certain point, or if it kicks a CEL if the PPM is not within a certain range. The anti-fouler trick would suggest that it's only above a certain PPM

(PPM= parts per million)