Nissan 370Z Forum - 09 Z runs rough

Hey guys! It's been a while! Anyway, we've had a few nice days here so I've been driving the Z just about daily. This morning I turned her on and noticed the exhaust had a different pitch. So I take her down the street and notice a slight loss of power, and that it was running pretty rough. No cels. Turn around and drive it home and it feels like it wants to stall. Let it idle in the driveway while a move another vehicle to get the Z into the garage and when I came back it had a Check engine soon light and was shaking. It's an 09, touring sport with 39K on the odometer. Only mod is an exhaust and the only other issue I've had with it was a steering lock. I want to say it's a fuel issue but I haven't filled it up this week and it's been running fine. I also want to say it's not getting a enough air but I don't think that's it. Gauges all read normal. I had to get to work otherwise I would have played around with it a bit more. Thanks for any guidance you can offer!