New owner - 650HP tuning and engine issues/questions


New Member
New owner of 2009 CTS-V since January 2024 (76K miles, automatic, black/black). I did full inspection in my local shop. It has 650HP modification package installed in 2021 by shop, up-graded exhaust, and lower suspension. This is not my daily driver, and I will not race or track this car, I plan to enjoy weekend rides (2K miles a year most likely). I put few posts with specific questions. I appreciate your comments, suggestions, or feedback.

Engine/Tuning questions:
  1. 650HP tuning/modification, up-graded exhaust, lower suspension – see attached
    detailed 2021 paperwork.
    1. Do you like this set up?, any feedback or issues you see with this?
  2. Engine light is on (tuning) and there is ~15 codes - See attached pictures:
    1. Anything high risk?
    2. Should I take the car to any local shop specializing in tuning to run some diagnostics and clean codes.
    3. Is there any way to change some engine tuning settings and get engine light off?
  3. Inspection showed very light engine and transmission leaks (there is nothing on the floor when parked). You can see some light oil under the engine and transmission fluid on front side near driveshaft. - see attached.
    1. Can I drive this and do nothing and just assume I need to do oil and transmition fluid refills and watch it?
    2. Or should I try to fix those, but I am not sure where to start and I do not want to be sold on high expenses by shop.
  4. TECHNICIAN NOTE from my inspection at my local shop: “While sitting at idle the vehicle has an intermittent misfire feel to it. While driving straight the steering wheel was a tad off to the left”.
    1. They checked alignment and it failed when measured – so doing alignment I assume may address “left”
    2. Any suggestions what can drive misfire at idle and can this be related with engine light , tuning set up and/or 15 open codes
  5. Any suggestions or comments are very welcome and I am fine to hear straight feedback or input.
Thanks for watching my post!


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