Find a new mechanic.Yes I am been thinking about these outcomes, my mechanic recommends going with exhaust
It will not. Get a catted downpipe - you get the same gains and no CEL. There is a -ton- of information available on this. A nice GESI high-flow cat is fine. Check my build thread for my recommendation - also ActiveAutowerke is popular for a no-CEL guarantee downpipe. You're interested in high flow, the difference between catless and catted is minuscule.Dp will give you cel without tuning
Find a new friendLol … he is also a good friend
Well, downpipe is a prereq for any reasonable power gain. You're not going to jam a JB4 on and see the gains you'd see if you had one. Or anything else. Sure it might snag you 10hp on it's own or something, but you need the exhaust to flow nicely if you're going to up the boost.downpipe --> a bit of both.
Yes the reason that kind of holding me back from going to the aftermarket cat- back system is that oem cat- backPersonal preference. I derive much of my "fun car" experience from the way my vehicle sounds. For me, an exhaust was higher up on the list (though a downpipe higher up than both). For a lower cost solution, I just went with a JB+ anyways, so is that an option to get you the noise plus a (small) power bump?