Code P0171, Troubleshooting Lean Problem?

I drive my car ~35 miles a day round trip during the week. I got a CEL with P0171 code while driving; the console light (green while cruising) immediately switched to white while driving after CEL activated. A day later CEL goes away a console light becomes green again while cruising but the issue repeats soon afterwards. The economy worsened from 24-25 mpg to 22-23 mph over the next few days. Idle was rough and low 400-700 rpm. On rare occasions I smell a trace of fuel but thought it was smoke from another car. I might notice some trace white smoke after cold start but I don't notice smoke from back while driving. 4 days later, I ran a few live scans. Sort Term Trim was 15-30% and drops towards 0% while increasing rpm to 3000. Long Term Trim steady at near 26%. I thought vacuum leak. As additional fyi, I live scanned the MAF and upstream A/F ratio 02 sensor while driving. Lamba was ~1 but spiked to 2 whenever the rpm drops. MAF was 0.2 lb/min while idle, about 1.6 at 3000 rpm steady and as high as 7 lb/min at 3000 rpm peak while driving. I did a smoke test, feeding the intake tube post-maf sensor. I noticed 2 missing clips for air bleed tube (after MAF) and a smaller B12 tube, thanks to my mechanic. Smoke leaked from those points but didn't appear significant. Hard to say. I looked inside the throttle body had black soot ring around choke; so, I cleaned around it with carb cleaner (I might have sprayed a little in there by mistake). Removed PCV valve and cleaned inside with carb cleaner; I saw a stopper on bottom side and spring on the tapered side. Not sure if this is normal for a PCV valve. I reinstalled PCV valve. Engine has been idling high 1000 to 1500 rpm ever since. Engine sometimes feels a little rough sometimes while foot on gas near 30-50 mph. As soon as I take foot off the gas while cruising 10-35 mph, the car hesitated before decel. I now have a permanent P0171 and new code P0507. 5 days later, I live scanned the O2 sensors while idle. Upstream A/F ratio O2 sensor is ~1 lambda and 0-20 mA current; Downstream O2 sensor is 0.6 V average, no spikes while idle. Only thing I haven't checked yet were the fuel injectors and fuel filter. I hope it's not those. Any ideas? I plan to clip the affected tubes and replace the original PCV valve, MAF, and MAP as soon as parts arrive. The only thing I haven't looked at yet was the fuel injectors and fuel filter. Any ideas?