If I go WOT from a dead stop while in sport manual mode, there's always a huge delay from the time I shift to the car actually shifting.

I can feel the car beginning to shift, and for a brief moment my rpm is climbing rather quickly ( example I shift at 6500, the rpms rise to 7500 then shift)

I dont know if this has always been the case, or im only noticing it after having the borla installed.

It feels like the car completely loses power for a brief moment while this is happening and i can hear "pop pop pop" coming from the exhaust.

Is this normal or the signs of a problem starting to develop?

Notes: Car is completely stock, save the borla cat back and a K&N drop in.
Issue is only in Sport manual

 

Did you get rid of the stock cat when you installed the Borla "cat back" exhaust? If so, you really shouldn't be driving that car without a new tune. If you still have the stock cat then you can stick with the factory tune, but these cars weren't designed to run a high flow cat or test pipe using the OEM tune.

 

I'm pretty sure he still has factory cat if he only installed a "cat back".
I would do a fluid flush on the SST if it's been a while.