Ive been going through an issue for about a month now. My car (lexus is200t 2017) would rough idle on cold start everyday at 1500 rpm and then once the warmup phase ends it drops to 800 and rough idling stops, i got a check engine light with P0128 code and rough idling confirmed. Funny thing is i replaced a new thermostat like twice in the last 6 months and also put a new cts and maf sensor and liqui molly, after the maf sensor (got a maf failure warning also during the 1 month and car went into limp mode) replacement and lqui molly the car was fine for 2-3 days and now the same symptoms are starting to happen and CEL came back. It seems something is preventing the car from warming up properly, it cant be a defected thermostat, what are the odds that two new oem thermostats that I bought were both defected. Please help me out with suggestions guys, thanks a lot.