Spot on diagnosis with those fuel trims, you either have a massive air leak and or a bad Maf maybe both. Best bet and cheapest to start with is to track down the air leak(s), replace any split or cracked rubber hoses, favorite is the intake bellows from Maf to throttle body. If you button up all the air leaks you should see the fuel trims return to normal. I dealt with a 2.2 last year that had high fuel trims that were down to leaks on the intake side and a cracked cam/rocker cover around number 4 plug. Replaced rubbers and had to fit a good used cam cover with new gasket and round rubber washers for the cover securing bolts. Once it was airtight the fuel trims returned to normal in an instant. Don't forget to clear the codes and rescan after running the engine.
Camshaft sensor code also needs looking at but solve the air leak problem first, clear the codes and see if that one comes back, if it returns then replace that sensor, it will be on the exhaust side of the camshaft, top of engine.