On my 1990 RS 305
"

-PCV
-Cat Converter
-Egr Visual
-Fuel Cap Functional
-Fuel Cap Visual
-Spark Controls
-Fuel Evaporative Controls Functional (this is the one I failed)
-Thermostatic Air Cleaner
-Air Injection
-Vacuum Lines to Sensors/ Switches
-Ignition Timing 2 BTDC
-Wiring to Sensors
-Fillpipe Restrictor
-Fuel Evaporative Controls
-OBD System Checks
-Carb./Fuel Injection
-Other Emission Related Components
-Oxygen Sensor
-Liquid Fuel Leaks

I passed all except the Fuel Evaporative Controls Functional...
"Low Pressure Fuel Evap Test"

"^^^ (Most 1995 and Older as of 12-01-07)"

Its where they stick a hose up to your gas tank and test for pressure.
Apparently pressure is leaking out somewhere from my gas tank or fuel lines...

Anyone know of a test I could do to try and help find the leak??
I dont want to take it into a shop to have the chemically dyed gas test done.

I failed the same test . . . you need to fill your gas tank before retesting in order to pass.

Leaking solder joint to filler neck, common thirdgen problem.

Common to aftermarket tanks, too. I have a sub 5 year old spetre tank and it's leaking a tad there too. JBWelded it for a few more years of service.

Agreed. Had the same problem on my 89 TA years ago. Ended up replacing it with the tank from my 91 and had Don weld the joint for added integrity. Haven't had any problems since.