I go to the gas station and add like 10 bux. Afterwards I smell fuel for a few mins. CEL comes on occasionally but gives a code for an O2 sensor(no CAT) Gas Cap also hisses when removed.

I have 1996 S-10 Blazer 4.3L 4x4 2dr.

im kinda thinking its the eVAP canister. but would LOVE to read all the advice given.