My P1317 code is gone, only to be replaced by P1138 ('96 SE7 5-speed). I took a look at the freeze-frame data and it looks like I may have a vacuum leak. I haven't had time to look at the live data for the O2 sensors yet. Is this most likely caused by a vacuum leak, or should I be looking at the O2 sensors instead? Freeze-frame data is pasted below:

DTC for which Freeze Frame was Stored P1138
Fuel System 1 Status Open Loop - due to detected system fault
Fuel System 2 Status Closed Loop
Calculated LOAD Value 54.51 %
Engine Coolant Temp 174.20 °F
Short Term Fuel Trim - Bank 1 24.22 %
Long Term Fuel Trim - Bank 1 6.25 %
Short Term Fuel Trim - Bank 2 -1.56 %
Long Term Fuel Trim - Bank 2 6.25 %
Engine RPM 1,966.00 rpm
Vehicle Speed Sensor 37.28 mph

 

What is the upstream O2 voltage on bank 1?

 

It bounces between 1.015-1.020V. Upstream Bank 2 bounces between.2-.9V. When reading live data, I also noticed my MAF readings were flat regardless of rpm.