Gross evac leak

Slow evac leak might make the engine slow to start but it won't prevent it turning over (cranking).

When the starting behaviour is difficult to diagnose or becomes illogical or inconsistent a malfunction of the immobiliser must not be overlooked.

a misfire can be mechanical as well as electrical
code p 0300 is random/ multiple misfires detected
low fuel pressure is a probable cause from a problem fuel pressure regulator or problem EVAC system not venting properly causing a vacuum in the tank and starving the pump
erratic could be from valve problems on heating
loose valve seat insert/s, incorrect valve clearance from faulty hydraulic followers, cam shaft lobe failures are all part of the mechanical reason for random /multiple misfires

If you just want to get through the smog test,they usually allow one monitor test to be incomplete and still pass.
If your area does,clear the codes and fill the fuel tank to the top.The other monitors should run and complete but the fuel tank monitor will not run with a full tank of gas so will not turn on the check engine light related to a tank vac leak.KEEP THE TANK FULL,and go get your smog test!

evap not evac ! prob an evap solenoid or cannister purge valve

Really, don't know who is doing the sevice, but when you evac the system that is when you check for leaks, a negative pressure is present after evac. the mechanic is SUPPOSE to wait at least 15 minutes with evac machine off, any variation of the gauge notes a leak, also there is a dye that is put in the system that helps to locate the leak, you might want to take it to someone else that knows what there doing.
Check this site out , it will help you to understand whats going on.
http://www.denlorstools.com/autoblog/2009/04/adding-freon-to-car-ac-gauge-readings-explained/

Yes. System must be evacuated in order to open line to change expansion valve. After replacing valve the system must be vac tested for leaks and recharged.

The purge solenoid is by the engine and is connected to the vacuum system. Check the vacuum lines going to this and the lines that may be connected to the vacuum port it comes from. Check for seals on the solenoid if it is directly in the intake manifold. Other things to check are the lines (plastic) that go to the charcoal canister and fuel tank. If the light has been on for a while I would start with the pugre solenoid. If you have a vacuum leak there it would go from small to gross.
Small leaks are checked by the ECM constantly, gross leaks are some that has broke/cracked.

probably the same problem as the '99. you probably lost too much coolant. charge with dye and check for leaks, (these things lose refrigerant normally, so you may not have a bonafide leak but check anyway) change the accumulator as a matter of course. evac the system and make sure you lose no vac over the course of 5 to 10 min. recharge the system for the proper weight (which is on the accum sticker) if you need detailed instructions let me know.

Found on my jeep that the high quality vac line to the evap bottle had split on the under side.