Hey guys so I got a pretty long list of codes that came up on my friend's car.

P0313 Misfire Detected With Low Fuel Level
P0300 Random/Multiple Cylinder Misfire Detected
P1349 Misfire Cylinder 4 With Fuel Cut-off
P1345 Misfire Cylinder 2 With Fuel Cut-off
P1347 Misfire Cylinder 3 With Fuel Cut-off
P1342 Misfire During Start Cylinder 1
P1083 Fuel Control Mixture Lean (Bank 1 Sensor 1)
P1085 Fuel Control Mixture Lean (Bank 2 Sensor 1)
P0171 System too Lean (Bank 1)
P0174 System too Lean (Bank 2)
P0128 Range/Performance Problem In Thermostat
P0735 Gear 5 Incorrect ratio

I had already changed the spark plugs, valve cover gasket, cleaned the maf, disa, and icv. Still can't find out what the problem is really.

Overall the car is having such a hard time starting, low rpms, and a lot of whistling noise.

Any suggestions guys?