Got 4 OBD II Error Codes Right Now

[Wilbur1035]

P0174; Fuel System 2/1 Lean. What the hell does that mean? Do I need to see a mechanic or can I diagnose and repair. I have better than a modicum of ability, just mostly old school stuff so I'm sometimes baffled with all of this computer controlled minutiae.
P0579; Speed Control Switch 1 Performance. So stop using cruise control? Will it prevent me from passing CA smog?
P0457; Evap System - Loose Fuel Cap. No it's not.
P0456; Evap System Small Leak. Good Lord, this could be anywhere? Most common starting points? Are people going to say, "Start at the mechanic"? Because I am close to doing that anyway but I want to save money to put back into my rig as upgrades, not to buy my mechanic a steak dinner at Ruth Chris.

Any assistance is appreciated, even if it's directions to another thread regarding the topics.

 

[JPNinPA]

Model and year please!
Ooo steak and there is a Ruth Chris in Cincinnati. Yumm!
I like medium rare. Thank you!


Sent from my iPhone using Jeepz.com mobile app

 

[JPNinPA]

Did you replace the gas cap? If so did you reset the codes?
Is the idle above 750 rpm?
HVAC only blow out defrosters?



Check these vac lines.
https://youtu.be/CbEMURzbHNc

While idling spray WD40 or injector cleaner around the vac lines listening for a change in rpm or stutter. Then at the intake near each cylinder to head. Leak is likely in the back three cylinders. On TJs the last #6 exhaust intake bolt is known to loosen. Or you may have a partially clogged injector with the vac leak.

Sent from my iPhone using Jeepz.com mobile app