Hey everyone!

I think I am getting a catless Hogan downpipe sometime this week. I was wondering if anyone has used something similar and what they did to avoid getting the P0420 code. I have heard of some success using spark plug non-foulers to move the sensor out of the direct stream of exhaust. Is there an O2 sim that works for my 2007 SS? I am just wondering because I have yet to find someone locally that can tune out the code in my ECM so I am looking for a temporary fix.

One last question....how much can I expect this to change the tone of my exhaust? I have the Magnaflow catback with resonator delete.

Thanks in advance MCF

 

I haven't done anything to the exhaust from the cat forward, just the MagnaFlow cat-back system. I'm curious to see if the cat-less downpipe has any significant effect on the exhaust tone and performance.

 

It is supposed to make it a lot louder and free up the exhaust a little bit performance wise...I just want the noise haha

 

well I contacted Will at Overkill and it seems as though he tunes out the code on all the tunes he sends out the door. So that is great news. anyone know the sound difference I may get with catless?

 

Matt,

As we both live in MI is there any law about us removing the cats? Would we get ticketed?

 

it is frowned upon everywhere. yes you can get a ticket but it is easier to get away with in states that doesnt require emissions testing

 

Ya we have no emmisson testing here in MI (yet)

 

Michigan does not do any sort of testing on vehicles so it wouldn't get caught that way. Technically you are suppose to have a cat. As for getting ticketed, that's up in the air. Honestly though, how noticeable is that for an officer to see on the road or notice on a routine traffic stop? It's not something visually obvious like window tint.

I may consider doing something in the future if it makes a noticeable difference with exhaust tone and performance.

 

the trick is to hollow it out so you get the gains but it looks as though you have it

 

You should free up sone horses. Pry no more than 10hp I would guess though. Mostly sound....ill upliad a video once mine is done for comparision. I have a few videos of mine how it is now on youtube