speedo goes crazy, car starts missing, loses power, then dies. Codes are:P0161 - O2 sensor heater circuit malfunctiom (bank 2 sensor 2)
P0340 - camshaft position sensor circuit malfunction
P0500 - vehicle speed sensor malcunction

Am I looking at big bucks to fix this? Where do I start?

 

well, its sorta one of those crystal ball type things , from the looks I would start with the cam postion circuit, an try to get the girl running an go from there . trace your wiring back look to see if its shorted out , rubbing against metel bracket, causing the motor to die, There should be a resistance test on the senser to check , sorry I dont have that info ,, prehaps someone else does. , Get you a repair book on the ole girl it will be your best friend.

The O2 senser I would say needs replaced , but thats not keeping it from running rite now , if moneys tight I would hold off on that,--of course it affect your fuel mileage a tad bit , so dont go like months to replace it- bank2 senser 2 should be the right side of the engine as you sit in the car an the #2 senser should be the one close to the rear of the vechile

An again were just guesing not being able to place our hands on the car ourselves the speedo senser should have a ohm test , possibly faulty wiring.

Sorry I cant tell you just what you need to do to fix the girl, you got a good start with the codes , an Iam sure folks can offer you some thoughts on this

 

I just had the same problems and all i had to do was replace the vehicle speed sensor, and it's all better. Mine had codes for bank 2 sensor, bank 1 sensor, speed sensor, O2 sensor, and Camshaft position sensor, and circuit malfunction. Did you recently replace the transmission?