running too rich or lean??

is there a way to check if the car is running too rich or lean…

I’ve messed around with the air/fuel mixture nozzle thingy which is located right on the side of the throttle body…

Does anyone know how to check and set it to it’s correct setting?

An A/F ratio gauge and EGT gauge can help with fuel curve tuning, or just get a dyno run and get them to check the fuel curve.

You can also try “reading” your spark plugs, but I’m pretty sure the conditions have to be pretty extreme for you to see what the engine is doing. Look at the electrodes of the plug and if you see:
WHITE: You’re running lean.
BROWNISH/GRAY: It’s a pretty good mixture burning in there.
BLACK: You’re running rich, and you have serious problems.