Nickvt90

I was having an issue with codes p0172 and p0175 around 80-85k and got it to go away with a new gas cap, cleaned MAF and the plugs were done at 77k. Also cleaned up the throttle body and took the intake manifold off just to peak inside the engine. There was no sign of any build up from what i could see and everything looked very clean but i went ahead and installed a catch can anyway. Since all this the car has ran fine with no issue, until about 2 weeks ago i started to notice a rotten egg smell whenever i would do a hard pull and i figured i might need to do the plugs soon. I didnt think much of it because im still getting the same mpg and I never need to add oil or anything, and than 2 days ago without warning I lose power and the check engine and vsc lights start flashing. I pull over, turn off the car, wait a minute and turn it back on and the light is gone. Than this morning on the way to work the check engine light is back and its showing p0172 again. No p0175 this time around but i wanted to know if anyone has any advice, its an 09 250 with 110k.

Nad1370

Freeze frame data while it set the code would help us find out whats going on with your fuel trims.

Although if i remember, Lexus had a Service Bulletin out for this issue.
L-SB-0032-09
It requires recalibration of the ECU.