Hello Scotty & Community.

I have 258k miles on my 2000 Tundra I purchased with 68k Miles. The truck has been incredible for me with common/regular maintenance since purchased in 2009.

Last week I was preparing for a 900 mile trip - I do all my own oil/filter changes but this time (regrettably) stopped into Jiffy lube due to it being 110 degrees in Arizona. I drove off their lot and moments later CEL. P0171. They reset computer and said "let us know if it happens again" - It did almost immediately.

Took to "A-tech" at Firestone and after paying (I won't say how much) to plug it into a computer and show me the same code I told him it had.. He suggested MAF sensor and due to my ability to install one, he said to replace it. He assured me it would solve it.

I replaced MAF Sensor - It did not solve - CEL again.

I installed the Original MAF sensor again, CEL. 

Today I had Upstream O2 sensors replaced w/ Fuel Filter (w/ original MAF sensor installed) - CEL again

I installed the (new) MAF sensor (now truck has 2 new upstream O2 sensors + fuel filter) - CEL again

I'm ~$600 in the hole with a CEL light still and truck thats not running right after taking it in for an oil change. Thanks for any help!!