Engine codes

[tonypaul]

I havnt drove my truck since before xmas but I have started up a couple times to pull in or out of the garage. Normaly I use my remote starter to start the truck but it hasnt been starting up. It would go through its crank cycle but not start. So I went to my back up key switch and it took a cranking of 5 or 6 seconds for it to crank up then it was idling super high. It would go up to around 2500 rpm to 1800 rpm and wouldnt come back down.

So today I thought I try it again. Same thing took a good 6 seconds of cranking before it would start and it idled real high. I drove it around the block and it didnt have no real power. If I mashed the gas pedal to the floor it would bog down. So I assume its in limp mode. I ran my AeroForce scan gauge in scan mode and came up with these 3 codes;
0101- mass airflow circuit malfunction
0121- throttle postion circuit range/preformance problem
0340- camshaft postion sensor circuit malfunction

I cleared the codes and started it up again- same thing it took a while to start, idled high. I didnt drive it just reved it a couple times to see if the idle would come down. Scaned again and 0340 came back up.

This truck was running so good last week. It would fry the tires all the way down the street.... Should I start by replacing the cam postion sensor?