Why do I get a STRONG gas smell through the vents 1st thing in the am in the col on 1995 Nissan Maxima

On a coId start when I turn on the vents, I get a strong gas smell through the vents. It lasts about 20 min. I have changed the fuel pump and checked the fuel lines. What else could it be? The car has 210k miles. There are no codes that come up

2 answers 1 comment
small leaks can be hard to find but #1 is correct.if you can't find it have it ck'd b4 your car poss catches fire.
Check the injectors and the injector rail for seepage.
I was told it could be the canister but wouldnt a code come up for that? Should the car be running when I check the injector rail? How do you check the injectors only?