My catalytic converter has gone bad on my 2010 RA Sportback. I don't want to spend the money on another stock cat when I am planning on installing a Ultimate Racing ceramic cat in the next year or so. I just had Ultimate Racing's 3" single exit cat-back exhaust arrive. My plan was to install all of my planned power mods at once and then have a shop tune it. I have spend a lot of time researching on this site, but have not yet found a clear answer. The car is my daily and want to minimize downtime(the "racecar" isn't very suited for daily duties).

Would replacing the exhaust from the down pipe back require me to get the car tuned? What about with the boost pill? The car is 100% stock other than an Evo X bypass valve. What is the best system to use for tuning?

Thanks for any help.

For 200ish you can get a used Cobb Accesport v2 and put the stage 3 map on there with the addition of a 3-port EBCS.

That's the route I went, I don't mind the older V2 because I don't leave the AP hooked up indefinitely for use of the gauges.

I currently have the Ultimate Racing Cat back and metal cat testpipe on my ralliart. I have the cobb 3 port, cobb drop in filter, go fast bits bov and the cobb stage 3 tune on. It runs good and currently has the 11.6 air/fuel ratio. The only issue is the lower o2 sensor reads it's running lean. Which in fact most high flow cats will do that on low and high hp ralliart/evos. Most people kinda just delete that code from popping up when getting it tuned. You might as well get the long downpipe as well so you have everything required for the stage 3 tune. If not you could just do a road tune after installing it on the stage 3 Map and have someone clean it up for you to fit your actual upgrades. You'll definitely like the gains with the aftermarket downpipe over the stock downpipe though. Seems to let the turbo spool a bit quicker.

Tune it.