I have a 02 rx300 that has been well maintained with regular service. I have the following codes.... P0100 mass air flow sensor, po110 intake air temp, p1135 air fuel sensor, p0172 & p0175 which i beleive are the o2 sensors. The idel is about 500 rpm's lower than normal and is a little hard to start and occaisonally stalls. I have installed a new mass air sensor, disconnected the battery and the above problems still exist. I checked the hose on the back of the air box and it is connected properly.

I read somewhere that a bad o2 could cause the other codes to come up. I dont want to continue replacing expensive sensors for the other codes if its the o2 sensors causing the problems. Can any one help???

 

Sounds like you may have an Idle air control valve problem.