Camshaft position Sensor

[AuroraTear]

Ok... here is the problem. Money I have this damn car the head gasket was recently replaced.2800.00 and change, the radiator and heater core also and 6 new spark plugs im up at 3400.00 now. only paid 5k for the car. Its a 1999 S80 T6. i had surging when i got the car back from the head job. I took the throttle body off and cleaned it and put it back on. 15 miles or so later It started skipping. and running really rough. All i had was a O2 sensot bank 2 sensor 1 no activity, now I have a camshaft position sensor advanced timing code, O2 bank 2 sensor 1 no activiy, random misfire all cyliders, and my rear O2 sensor reading rich then lean. when it shudders/skips im giving off black smoke out the rear. Driving normal its ok. What do I do??? i already bought the O2 sensor and the camshaft position sensor. my oil is clean it has been changed 2x's since the head job and its been less 1k miles.... Please help me. im outta money and outta options

[boosted5cyl]

Bad timing belt job? The VVT unit can cause headaches for people not used to working on Volvos. Actually I can cause headaches for people who are. Take it back to where the head\timing belt was done. If they try and tell you that the sensor is the problem (possible but unlikely) call their bluff and ask them to show you the oscilloscope readout

Another possibility is the CVVT solenoid is cludged up and not working, this usually causes a different error code however.

[AuroraTear]

Umm Actually... MYY car got low on oil when i first got it. I had a camshaft position sensor error and THrottle body failure, fuel pump shortage and some others. After taking it in for an oil change the check engine light went out and i had te comp cleared and got it inspected without a problem. After this it drove for a long time until it blew the head gasket. maybe changing the oil again? Maybe when he did my head he used cheap oil... I dunno I jsut know I cant afford anymore repairs at all