Recently, my SES light came on and I pulled the codes using a Peake code reader. They are listed below using the Peake codes for table "0F":

1. "0D" - Pre-cat oxygen sensor heater, cylinders 1-4.
2. "1C" - Mixture control, idle, cylinders 1-4.
3. "1D" - Mixture control, idle, cylinders 5-8.

I replaced the pre-cat oxygen sensor and now I'm getting these codes.

1. "5D" - Evaporative emission system.
2. "1C" - Mixture control, idle, cylinders 1-4.
3. "1D" - Mixture control, idle, cylinders 5-8.

Does this sound like a possible vacuum leak or could there be something else wrong here?

TIA,
Richard