14turbos

Anyone know if it’s safe to run a Cobb OTS stage 2 tune on a 991.1 turbo s with BMC drop in filter and quicksilver catless exhaust?
I know their stage 2 requires an aftermarket exhaust , just not sure if Using a test pipe would cause any lean conditions over a high flow cat.
I have 02 extenders already installed and no cel lights .
thanks

MotoJB

You should be GTG. I checked with my tuner and he told me I'm GTG on a stage 2.

I was running a Stage 2 with a catless 3" x pipe...now with cat bypass tubes and stock muffler setup.

I was told to run stage 2 (for the right gas of course), with SBR (standard boost response). I'm currently running stage 2, 100 octane with cat bypass tubes/stock muffler. No problem per my tuner.

How's the drone with that catless quicksilver?

14turbos

thanks for the reply . The drone isn’t that bad unless you keep it in the 2200 - 2300 range . At that range in 7th gear I’m around 80mph. Had a long trip this weekend with the wife and she said it didn’t bother her . And she normally complains about stuff like that . She hates my zr1 because of that and I thought the quicksilver was a little worse . Although I was downshifting to 6th gear to reduce the drone during some inclines in the road . 6 th gear was perfect. The sound is so much better now I actually enjoy the car more . Now to start running and more mods to come .... 👍🏼

MotoJB

I'll add that I didn't use 02 extenders as I'm going to tune out the CEL with COBB.

2fcknfst

Is there a benefit to tuning it out versus tuning it?

I would think that the ability to retain a redundant set of sensors will never hurt...

MotoJB

No benefit that I know of...aside from not having to pay the for the extenders.

Ttz06vette

Can you also tune out the readiness check on the sensors to pass emission inspection? I’m using the extensors plus tune to be sure but haven’t had my inspection due yet.

2fcknfst

I would think there would be a benefit to keeping them for mileage (long term fuel trim) - if the ECU only has one set of O2s to 'average' against, the long term measurements could be off, and/or the ability to make more accurate mixture measurements - or am still thinking like an import guy?

On past projects I may have disconnected the fault circuit in order to avoid CELs, and even added additional wide-bands - the more data the car can use, the happier it will ultimately be.