Error Code P0455 NB Miata

[TRIPL3R]

Hello i was inquiring about this trouble code it says gross evap leak any suggestions?

[—atank—]

Could be the gas cap P0455 is a gross leak, the fuel system is not holding pressure...ERG, check lines going to intake manifold into to charcoal can...start cheap and simple first.

[TRIPL3R]

i tried tightening the cap its secure

[mini_fd]

My code was thrown because one of the lines that vacuums to the fuel tank under the rear parcel had a hole from rubbing against a pinch weld on the left side that connects to a purge control

[— Agent☣Orange —]

One of the guys in my local club went through this ordeal and disassembled half is his Miata checking this and that. In the end, it was a new OEM gas cap the fixed the problem, even though the old gas cap felt tight.

[jchapin47]

My situation is a little different--I think. If I turn off the check engine light by disconnecting the battery, it takes some time, a day of driving, for it to come back on. I replaced the EGR valve and no difference . Also bought a new OEM gas cap. Any ideas?
JohnC

[— kung fu jesus —]

Disconnecting the battery won't solve it. Once the system runs through its system of readiness and the problem hasn't been fixed, it will throw the code again. You also wouldn't pass an OBD inspection.

It would also be helpful to know what year you have.

The FSM should be available online as well. It may detail methods to systematically check the components to isolate the issue.