Hello everyone,

I have a Honda Civic 2007 EX 4 Door Sedan 5 Speed Automatic with ~168,000 miles. For the past couple weeks I've been battling with a check engine light coming on with code P0507 (Powertrain): "Engine idle RPM higher than expected". I bought an ODB Bluetooth adapter to get the code also, here is the "Freeze Frame" data if it helps (have to hand write, exporting it there's too much formatting code).

*EDIT* Forgot to include: sometimes the check engine light goes off on its own for a day and then will come back on.

Calculated engine load value (EngineLoad) 33.33
Engine Coolant Temperature: 170.6
Short term fuel % trim Bank 1: -7.81
Long term fuel % trim Bank 1: -6.25
Intake manifold absolute pressure: 0.32568467811
Engine RPM: 943
Vehicle Speed: 0.0
Timing advance: -5.5
Intake air temperature: 46.4
MAF air flow rate: 3.82
Throttle position: 13.72
Run time since engine start: 1187
Commanded EGR: 0.0
EGR Error (EDGRE): 99.21
Commanded evaporative purge: 42.35
Fuel Level Input: 48.23
Barometric pressure: 0.99679249967
Absolute Load Value: 22.745098039215687
Command equivalence ratio: 32626.0
Relative throttle position: 2.35
Absolute throttle position B: 30.98
Accelerator pedal position D: 20.39
Accelerator pedal position E: 9.8
Commanded throttle actuator: 2.74

Here is what I have done so far:

Removed air intake, cleaned throttle body carbon out as best as I could.
Reinstalled air intake with a few new clamps.
Attempted to check for vacuum leaks (using two methods: diluted soapy water, and brake cleaner) and I did not notice any RPM jumps.
Removed MAF sensor (it looked pretty clean) but I cleaned it with MAF sensor cleaner anyway.

My questions are:

Anybody have any suggestions on what else to take a look at? Would replacing spark plugs help ? I'm pretty positive they've never been replaced.

If I ultimately need a new throttle body I'm confused on just parts in general. Apparently there's multiple choices like "USA Built" "Canada Built" and "Japan Built" and I don't know which is better or if it matters but am curious of how much this SHOULD cost?

I'd appreciate anybodies insight and suggestions on what to do / look at next, thank you for your time!