11-20-2020, 02:26 PM
Hello Vidas, and all I am not an expert, but I understand you failed emissions test. I am guessing its California.
1995 and older vehicles require an Low Pressure Fuel EVAP Test. They do use Nitrogen gas because it is an inert gas.
They test the the EVAP system by pressurizing the system at the filler neck with a hose the goes through adapter that wil be similar to the gas cap that is tested separately. They pinch the hose at the EVAP canister to seal the system. For diagnosing EVAP leaks I have seen licensed Smog Repair Stations use a Smoke Machine that puts visible smoke in to the system that will come out of the area or areas that are leaking. It cant be that expensive to use the smoke machine and then you could fix yourself.
Hope this helps
Regards
1995 and older vehicles require an Low Pressure Fuel EVAP Test. They do use Nitrogen gas because it is an inert gas.
They test the the EVAP system by pressurizing the system at the filler neck with a hose the goes through adapter that wil be similar to the gas cap that is tested separately. They pinch the hose at the EVAP canister to seal the system. For diagnosing EVAP leaks I have seen licensed Smog Repair Stations use a Smoke Machine that puts visible smoke in to the system that will come out of the area or areas that are leaking. It cant be that expensive to use the smoke machine and then you could fix yourself.
Hope this helps
Regards