I have a 2006 GMC Yukon 5.3 vortec GMT 800. Runs great the random lifter tick noise for 1 minute then its gone, recently I've been having random times where it'll idle rough and misfire a lot and feel like its out of fuel. but the exhaust also smells a little of fuel so its not burning it so I assume I have a massive air leak. but the fuel smell went away and still misfiring. then it'll drive perfect maybe stop at a light at idle it'll be fine then start misfiring. multiple codes for o2 sensors and lean bank 1 & 2 but when its running fine I can hit the gas and accelerate without an issue so I don't think its a fuel deliver problem. I'm not sure where to start.

 

I had a random misfire issue on my '22 Camaro ZL1 and it turned out I had a faulty spark plug. Had to replace it and it's been running smooth ever since. Not sure if it's related but I also recently filled up with some bad gas, so it's possible that was the cause too.