HELP .. Engine problems started last night.

So we were heading out for the night and the car started sputtering. I though at first it felt like we were running out of gas (it's happened a few times) so we went to the gas station and filled up. Seemed okay for about a mile and then it started shuddering again. When I stepped on the gas there was no go and then the Service Engine Soon light came on. It only did it at slower speed .. once I got on the highway to get the car home it ran fine but once I was off the highway it started again. I have a scanner and when I got home I scanned it .. Here is what came up.

P0152 - O2 Sensor Circuit High Volts (Bank 2 Sensor 1)
P0154 - O2 Sensor CKT No Activity (Bank 2 Sensor 1)
P0302 - Cylinder 2 Misfire Detected
P0300 - Random/Multiple Cylinder Misfire Detected

I just had headers, ory, underdrive pulley, plugs, wires, 160 thermostat, trans cooler and gears done 300 miles ago. He supposedly removed the codes for the O2 sensors for after the cats (since I have no cats anymore) but I'm wondering if these codes are for one of the sensors before the cats that might still be in use.

Please help so I can call him up and figure it out. His shop is an hour and fifteen minutes away so I'll probably haul it out on a trailer to him. I just want to understand what's going on. It never had a problem for the past 300 miles since we got the car back until last night.

The 02 codes are for the same sensor on the passenger side (precat), check to make sure the connection is good and the wiring didn't get burnt against the header somewhere. For the misfire codes check the plug and wire on #2.

Edit: Also, if you find the 02 sensor harness wires burnt/arcing against the header check your ENG SEN fuse too.

I'll check both of those today. Should I conider wrapping my headers if that is the case?

Nah, I'd just make sure the harness stays clear of the header. You can look up the codes/diagnostics for more info at www.gearchatter.com

Usually with LT headers you switch the o2 sensors to the Bosch 13111, so if they are still stock, this could be an issue. But sense these two codes are for the same sensor, I second to just check it out and see if it didnt get burned up on the header. Save yourself the money of sending it to someone else. These should be an easy fix.

The 02 codes are for the same sensor on the passenger side (precat), check to make sure the connection is good and the wiring didn't get burnt against the header somewhere. For the misfire codes check the plug and wire on #2.

Edit: Also, if you find the 02 sensor harness wires burnt/arcing against the header check your ENG SEN fuse too.

agreed

Okay .. didn't find any wires so I got my brother to get me two Bosch 13111 sensors. He works at Carquest so I get all my parts from him that I can. Great deals. His price on them was $44.