So I've had this problem for a while and I've been living with it since it really didn't affect performance or anything; but alas I need a smog so have to solve it. Previously we replaced the purge valve and charcoal canister which were indeed leaking and failed the smoke test.

However I have a persistent small evap leak. I am dreading that it is the fuel filter.
Today I opened up the access hatch which is in the trunk area and it does have a gas odor after the car was on for 2 mins in that area.
My question is, can I put a smoke machine in the gas cap to see if the smoke leaks out from the filter?

Do the photos look like leakage residue?

Thanks for your time reading or providing an answer!

Yes, smoke testing through the gas cap is a common method to pressurize the system and find leaks. The residue in your photos is suspicious and indicates a past or present fuel weep, likely from the filter housing gasket or connections. That area smelling of fuel strongly points to it being your small leak source. Test it.

Looks like it to me. I had a similar one and have been riding a very hacky job since September in mine, but I cleaned the area really well and roughed up the area of the cracks with some 60 grit because that's what I had. I then slathered JB weld marine over the cracks, let it cure for 24 hours and it's been solid since then. I really don't want to drop the axle to swap the filter so eventually I may widen the access hole and change it from the top.

I vaguely remember reading a thread where someone showed an easy way to get to the fuel filter without dropping axle. Cut a hole in the floor above the gas tank and make your own access panel…

Thats exactly where my leak was. I could clear the check engine light but as it gets closer to a half tank it would come back. After cleaning it up the crack was almost unoticeable like it was a seam that was meant to be there. I ended up filling that void up with epoxy. I'll replace the whole cover when I replace the fuel pump.

Interested in this topic. Can someone kindly mark up the pic and show where the leak is originating from?

so if there is no leak, the top of the fuel filter should be relatively clean and white/off white?

thanks