2010 Sierra 1500 5.3

[All Terrain Trav]

2 weeks ago my truck decided to go haywire. I've had a K&N CAI since I bought the truck new, and a Blackbear in person tune since April. First check engine light was showing a misfire. Changed the #7 plug which was fouled and everything seemed to be fine. A few days later I was getting codes for system lean, banks 1 and 2. A few days later the check engine light went away. Few days later back again, but onstar said it was history codes. Went away again....took truck to dealership for oil change and tire rotation. Got the truck back drove a few miles and the light was back. Today I noticed a pronounced ticking coming from the engine. I just ordered the Autocal from Blackbear today to get the truck back to stock settings before I take it in. I tow alot with this truck and it already has 40k miles on it. Am I killing this poor truck? It gets serviced every 3000 miles religiously. I'm at a loss here.

[Stevens03]

No your not killing it... but certainly sounds like somethings not right. Keep us posted.