It has been happening for approximately one year happens every couple of weeks, doesn’t last too long I shut off the engine and wait about 30 minutes then it’* back to being normal I am running perfectly fine. Had the spark plugs changed and also replaced the throttlebody.

PO300 tells me it'* at least 1996 or newer. Regardless of what you drive we need more info to help you.

[From the second thread]
2012 Buick enclave
Also smell of gas, has been happening for approximately one year happens every couple of weeks, doesn’t last too long I shut off the engine and wait about 30 minutes then it’* back to being normal I am running perfectly fine. Had the spark plugs changed and also replaced the throttlebody.

[From the second thread]
What other codes? All modules not just engine.

Is this on the 2012 Enclave? If not, what year/make/model is it?

How many miles on it?

Did this problem start before or after replacing the spark plugs?

Did this problem start before or after replacing the throttle body?

Does this happen soon after refilling the fuel tank?

Merged duplicate threads. Please do not start multiple threads for the same issue.

it doesn’t always, sometimes no rhyme or reason, it has before though immediately after filling tank

Replace the purge valve.

Yep. Purge valve, because:

- It might be at fault
- If it isn't at fault now, it will be soon
- All other troubleshooting will be tainted by the knowledge that the purge valve is likely the problem

Yes we did that already, sorry forgot to add