How to open wrongly closed fz16 fuel tank cap

Small EVAP leak
Missing or loose fuel cap
Incorrect fuel filler cap used
Fuel filler cap remains open or fails to close
Foreign matter caught in fuel filler cap
Evaporative Emission (EVAP) canister or fuel tank leaks
Evaporative Emission (EVAP) system hose leaking
Fuel tank leaking

- Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking

This could be as simple as a dirty fuel filter or a clogged vent line. When you open the gas cap do you hear a hissing sound? If so you are have a problem talked "a vacuum lock" after to so much gas is used from the tank there becomes a vaccum and if the vent can't allow ample air into the tank the gas will simply stop flowing. A clogged fuel filter will cause a lack in fuel supply. Both of the problems I have stated will "will starvea the bike of gas causing poor performance. Check into the easy and should you still be ha en problems please feel free to write me back

P0441 JEEP - EVAP Purge System Performance
Possible causes- Missing Fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- Incorrect fuel tank vacuum relief valve Tech notes Loose or damage fuel tank filler cap may trigger the P0441 code

Hi, Rahul the answer to this question is way above my pay grade and for this situation, I would call my local dealer or reputable shop's service/parts department and inquire about any possible quick fix, answers, or parts inquiry.
Good luck and have a wonderful day.

P0442 - Evaporative Emissions System Leak Detected (Small Leak)

P0455 - Evaporative Emissions System Leak Detected (Gross Leak)

This diagnosis detects leaks in the EVAP purge line using engine intake manifold vacuum. If pressure does not increase, the ECM will check for leaks in the line between the fuel tank and EVAP canister purge volume control solenoid valve under the following vacuum test condition. The vacuum cut valve bypass valve is opened to clear the line between the fuel tank and the EVAP canister purge volume control solenoid valve. The EVAP canister vent control valve will then be closed to shut the EVAP purge line off. The EVAP canister purge volume control solenoid valve is opened to depressurize the EVAP purge line using intake manifold vacuum. After this depressurization is implemented, the EVAP canister purge volume control solenoid valve will be closed.

Causes:
- Missing Fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- Incorrect fuel tank vacuum relief valve
- Leak is in line between intake manifold

Solutions:
- Re-tighten or replace fuel tank filler cap
- Replace damaged or leaking EVAP canister
- Replace damaged or leaking lines.

Toyota P0441 - Evaporative Emission Control System Incorrect Purge Flow

Possible Causes:
- Missing Fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- Incorrect fuel tank vacuum relief valve

Possible Solution:
- Retight or replaced fuel tank filler cap
- Replaced damage or leaking EVAP canister

P0441 - Evaporative Emissions Control System Incorrect Purge Flow

Possible Causes:
- Missing Fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- Incorrect fuel tank vacuum relief valve

Solutions:
- Retight or replaced fuel tank filler cap
- Replaced damage or leaking EVAP canister

The fuel system in this car with two taks is a little complicated. Not only is there a swithcover valve in the trunk but there are also two nonreturn valves in each wheel well. They are electrically opposite which means that when one is open the other one is closed. This is because as fuel is used from one of the tanks then unused fuel from the fuel rail will be returned to that tank. If a fuel non return valve stays open when it should be closed fuel will flow into the wrong tank. This is bad because no fuel is being taken from that tank and it will fill up from the excess fuel from the other tank overflowing the cap and run down the side of the car. If the guage of the overflowing tank reads empty I would think that the plastic float in the tank level unit has cracked and sunk. You can check it after the tank is well down on fuel. Itis accessible after removing the right taillamp assembly.

Somethings wrong withthe fuel tank cap..the air vent is blocked thus its kinda forming vaccum in the gas tank.
Try to unblock the vent at the fuel cap..or replace the fuel tank cap.
Hope this helps!