Hey, yall. I have a 2003 chevy suburban 1500 z71 flex fuel. Over the last 2 weeks, it started running a little rough on idle. Ran a bottle of injector cleaner through it with better fuel for 2 tanks, it mellowed out. Flash forward to yesterday - im driving along at 55 and I stall. Weird, but it happens. She turns over and is fine for an hour.
Stalled again. Okay, let it sit and well give another go. Makes it 150ft before it falls on its face. Takes 10 minutes of sitting to turn over. Towed home, checked the codes. On p0449 with 0455 secondary. Swapped out the evap purge on the throttle body, swap in a new relay. Runs mint.
Go to work this morning, falls on its face after 15 miles. Get an oil change, buy a new crank shaft positioning sensor, gimp it home. Pulled the battery, pulled the starter, put in the new sensor, buttoned it all back up. Now it won't even turn over.
its still only reading the same code, the handheld and tablet readers aren't giving me any information at all.

Anyone????