trouble code thoughts.

[markanthony]

I went threw the cats on the 99. The rear on the driver side broke down and was rattling. The front on the pass side plugged up. So I cut the front two off and replaced the rear two. I am getting codes....

P0155 Upstream Heated Oxygen Sensor Heater circuit fault - Bank No. 2.
P0156 Downstream Heated Oxygen Sensor circuit fault - Bank No. 2.
P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1.
P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1.

My thoughts are leaning at both the 02's and a fuel pump. I have replaced fuel filter. I have CAL, replaced pcv and 90 elbow, have accel cop and motorcraft plugs replaced 6 months ago. Not sure were to go from their.

Any ideas..

Thanks.