Is this gas cap for the pre-AEL D1? My 97 D1 has a round canister, not rectangular, and code number on plate shows it to be pre-AEL. Have been chasing 1447 and 0446 codes. Changed canister and valve. Vac line clear to engine and throttle body port cleaned out. Gas cap makes big "woosh" when removed. At some point in the past the ECU was swapped from donor vehicle (unknown what version evap). Gas cap from unknown truck, might be oem, might be a swap. Has "12" in the center of the yellow part.

As always, thanks for your help and guidance.

 

I dont think it really matters Buzz.
I think the non-AEVAP and the AEVAP use the same gas cap.
However you could buy a new one just to be sure, they sell for about $10 at your local parts store, just make sure it is a NON vented gas cap.

 

I think you are chasing your tail untill you verify the calibration number on the ecm.

 

Advanced evap gas cap is tethered. But like spike said, I don't think it really matters.