EVAP systems readiness test Not completing!

[martinsw]

I have tuned my 79 vette conversion Ls1 (99 fody pcm) - it is currently running great - I no longer have any DTC's coming up - have done the gm recommended drive cycles, driven >100 miles, BUT still can't get the
"once per trip tests - EVAP systems" to complete (shows red - incomplete). All other tests complete with no errors.

Does anyone know what is required for this test to complete? Would turning off some DTC's not allow this test to complete?

Trying to get ready to smog my conversion, believe they will fail me automatically in California if this test does not complete....?

Any advice appreciated.
Steve

[crash dummy]

I have tuned my 79 vette conversion Ls1 (99 fody pcm) - it is currently running great - I no longer have any DTC's coming up - have done the gm recommended drive cycles, driven >100 miles, BUT still can't get the
"once per trip tests - EVAP systems" to complete (shows red - incomplete). All other tests complete with no errors.

Does anyone know what is required for this test to complete? Would turning off some DTC's not allow this test to complete?

Trying to get ready to smog my conversion, believe they will fail me automatically in California if this test does not complete....?

Any advice appreciated.
Steve

Actually you are fine, Cali lets you get away with any 2 of the monitors not set but you can't have any DTCs , You have no clue how many people are running around with the EVAP not set.

[EC_Tune]

Do you have the pressure sensor in the tank? Do you have the carbon canister from the donor vehicle? If not, the EVAP monitor will never set.

[martinsw]

Do you have the pressure sensor in the tank? Do you have the carbon canister from the donor vehicle? If not, the EVAP monitor will never set.

I don't have the donor vehicle tank pressure sensor - I am going to try and use my 79 vette charcoal cannister. Was hoping to electrically rig any evap solenoids (resistor to +12 v so PCM thinks its there). I am not sure about the electrical circuits for the tank pressure sensor - can that be dummied up also?

With some luck, they will let one test not completing pass?

[EC_Tune]

Nope, the tank pressure system must be intact in the tank or it won't work.

[RomansDesigns]

Cat conv readyness and evap readyness go to yes if you turn the codes off.
In street rods I turn off the appropriate codes so they don't turn on any annoying lights and the status sensors go to yes when they are turned off.