I have been researching, and i wanted to turn my single exhaust ls 3.1 v6, into a dual exhaust. but the problem i hear alot of is that if you change the exhaust your check engine light will pop on due to lack of backpressure is there a way to get a better preformance exhauust, and not have any lights pop on. i basically want more deeper sound to my monte carlo, and as much performance as i can gain.

thank you Jacob

 

I am considering this as well. This is the first obd2 car I've ever dealt with (my 99 ls) and I don't imagine how that would cause a cel? Also, I own a Lincoln and people on my board always joke about the GM guys claiming they 'need' backpressure. Whats the deal with this? I hacked the mufflers off my Mark and killed all backpressure, and I have plans to cut out all resonators, and run straight pipes right out, and have driven in Marks like this and they run fine.

I am interested to see peoples' response to this. I have a small exhaust leak where the exhaust pipe leads into the muffler, that I plan on patching up with jb weld until I can either replace the muffler or do something else.

It looks like there are 2 cats, or is one a resonator? Also, where is the 02 sensor in this badboy, because if these cats are 'unmonitored' by an 02 I'll just gut em all out. That sound improve sound.

 

Actually I'll just patch up the muffler thats on it now. This will never sound as nice as my 4.6 so I won't try. Add a new muffler and enjoy!

 

You won't get a check engine light by any catback work on your monte (ok, maybe if you plugged it up really bad, so backpressure went through the roof- but not doing anything normal). On my 3100 96 ls, I drove around for a couple months with it cut off just behind the cat (long story)- and I never got a check engine code; before that I had a glasspack in place of the muffler, and a resonator delete.

As many have said before, don't do any cat back exhaust work for the puprose of gaining power- even a wide open- free flowing system isn't going to gain a noticeable amount ona basic bolt on engine, so it isn't worth it to pick one setup over another to pick up that extra 1/2 awhp. Instead- base your choice on what sounds good to you.