Hey Gang, as the title states I've been perusing this forum for years. My wife bought the G6 brand new right after GM announced they were killing the brand. It's been with us since that day and I inherited it when we had our first baby. I've grown over the years to really like the car, I'm a sentimental guy and this car is part of my family. Enough of the sappy feelings. I've got 150k miles on the engine with nothing more than regular oil changes and a spot in the garage. Recently I've noticed the car will not accelerate at highway speeds without downshifting. It's way over due for a tune up, I know this but as I've read here folks have said catalytic converters, transmissions, etc. could be the culprit. So, I'm wondering if an ODB2 scanner will tell me what the issue is and if so, do any of you have any suggestions of what make/model I should pick up? Thanks in advance for any recommendations or insight you have. I look forward to putting another 50k on the car before putting it out to pasture!