salimshah

We cant rely on what the ECU is getting and how it is trying to correct till we are ensured that battery is fully charged, sensors are good and the wiring is proper.

I can only state the obvious that you are having timing problem. OCV, timing belt, cam/crank position sensors can be the source of problem

Salim

Ldguitar

I am having the exact same issue. I have replaced the following sensors with denso dealership parts. Both air/fuel sensors. Maf sensor. Tps. Coil packs. I flushed the coolant system and got a new t stat from lexus. I went as far as to pull the cam phasers apart to check for sludge and clean them. If I pull the ecu fuse and let it reset the car will run fine with out any missfire indefinitely. But the cel will come on for p0125 p0171 p0172. If I shut it down and try to drive it again it starts misbehaving and throws ever code relating to both bank a/f sensors and misfires on bank 1 only. I've scoped my injectors and they look fine. This is where it gets weird. If I activate vvt on bank 2 it stalls. But will actually raise rpms if I activate bank1. At 40% and higher throttle at around 3000 rpms it will stop the misfire and run great. But if you just drive it conservitavely it barely moves and pops and shudders. But like I said all this disappears when I reset the ecu and drive it. It's only when I shut it down and try to drive again will it start this bull crap. I can provide data log info if some one can help. I'm using a snap on modis ultra.

Ldguitar

Also read somewhere that there was a tsb on an update reflash from the dealership. But haven't heard back from the dealership yet.

salimshah

What happened between when it was running fine to the current condition?
With hundreds of RX on the streets, I doubt that a flash update will fix the problem (it may tweak it a bit if any). Ignition is again based on timing (belt, sensors and position) and OCV.

Salim

Ldguitar

I bought it with 111k almost 2 years ago. It ran great with no issues. It started around 125k as a bad a/f sensor so I replaced both. It went back to being ok for about 4 weeks and that's when things went bad and parked it in my garage. My kids take up most of my free time so I just worked on it when I had the chance being it wasn't a primary vehicle. But it really seemed to have come out of nowhere prompting me to start checking sensors, wiring and timing. Most sensors were fine and worked as they should (to my knowledge) and the ones that weren't I replaced with genuine oem parts. The only progress I made was it doesn't stall anymore and it will run great after ecu is reset but falls back when you shut it off and start it up again.

artbuc

Ldguitar

Ok, Didn't think it was rude.... figured since we were having what sounds to be an identical issues that we could maybe both find some answers.

O1GS43O

ok just got the denso o2 sensor in bank 1 ill report back what happens.

O1GS43O

the valve cover gasket was leaking. so while i had it off i changed the plugs. the knock sensor hack s to feed one knock sensor output to both bank inputs.

O1GS43O

my situation is way different then the normal one. unless you have a mom that drives with the check engine light on for ever and only says something when the car is unable to idle. lol

in my situation the computer was doing all kinds of crazy stuff to combat the issues cause they went on for so long. once i unplugged the battery over night and started it i got all the codes i needed and it was all due to bad o2 sensor. always get denso's

salimshah

I went through quite a bit of effort to put together [with the help of the members] 'having problems start here mega thread" a sticky. It states that before chasing any CEL, one must clear them and wait for first one to pop up. While responding to the posts, I forget to remind them to clear codes before chasing a CEL.

On OEM, some members think I am Lexus/Toyota bias. Well I will gladly pay the premium on the sensor to be reassured that the new part is good. I have been publicly shamed on my stance but I have not budged.

Good luck.

Salim