Ac Molina

Any recommendations for a 2013 G37 journey, when I'm driving it hovers around 2,000-3,000 rpm at 20-25mph, when I give it more gas the rpm goes higher, sounds like I'm racing when only going about 40mph. When I slow down, it feels like the engine is going to stop. Will post video tomorrow. I thought it was dirty trottle and cleaned them already, also changed spark plugs about 8 months ago. When I rechecked the throttle, I found my #2 spark plug ignition coil screw loose. Tighten the screw and recleaned throttles, ran little better, but still high rpm, check engine light finally came on after driving 30 mins and took to autozone, told me my negative battery cable was dirty. Cleaned the battery cable and worked for about a week, then started same way. Changed the battery and cleaned the terminal, but still running a little high, just not as bad as 6-7rpm. running about 3-4rpm when driving around 40-45mph.

Said Amir

When idling is your RPM also high? If so perform an idle relearn. There are videos on youtube on how to perform it.
Are you modded?
Have you tried manually shifting the gears?