Truspeed

I recently bought a 2012 EB and have ran into a few issues. I do have an extended warranty but I am getting some push back from the dealership on the root cause. I am having serious shuddering issues from 2000-2500 RPM in 2nd gear, issues with surging while on cruise control, overall struggling to accelerate and a loud sputtering noise when downshifting on cruise. The dealership is saying that the exhaust (MBRP) and intake (Airaid) are causing all these issues which is not true because they were all there prior. At this point, they want me to make it stock and then have them look through it again. Anyone close by that has their factory parts sitting around so I can swap to get these issues corrected? Any help would be appreciated.

Sirikenewtron

When was the last time you changed your plugs? If it's been a while I'd start there, who knows you may be able to avoid the headache of dealing with the dealership, finding OEM parts to put back on.

Truspeed

Unfortunately, I have changed the plugs in the last 2000 miles and drilled the hole in the intercooler. No luck!