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Usually knock sensors do. I've heard of oil control valves not throwing codes though. In this case you wish you had a check engine code so you could pinpoint the problem.
Did you have the knock sensors replaced with toyota ones or aftermarket ones?
Aftermarket. What I don't understand is this..........if aftermarket sensors don't work well with the car, wouldn't the check engine light be on after replacing the old ones with aftermarket?
At this point I'm just going to take the car to a Lexus dealership and have them tell me what's going on.
I honestly can't tell you why they wouldn't trip the CEL. The 1MZ is very finicky about its sensors, anything having to do with timing has to be OEM parts, one small issue and the whole engine will run completely out of whack.
Good luck at the dealership, I hope they can pinpoint your problem.
Also check your thermostat. If the car is running cold the ECM thinks the engine has not warmed up yet and it will prevent shifting into overdrive. If the thermostat is right on the edge of acceptable temperature this may be why you see a correlation with stopping the engine or turning on the AC. This happened to me on another Toyota vehicle. Replacing the thermostat fixed the problem.
So after having my car for 2 days I get the dreaded news that I need a new transmission. The local Lexus dealerships service department looked at it and that's their diagnosis. They quoted me $4200............I didn't even pay half that for the car so I'm certainly not going to pay them that much. I've got several places working on quotes for me so I can make the best decision tomorrow.
The one good thing is that they did give me a loaner car for 2 days......... A 2014 Lexus GS 350, and now I want one!!! 😄
Can a clogged cat cause the OD not to engage? Only reason I'm asking is because when I'm at the light it hesirates as if it has a clogged cat and takes forever for the car to accelerate. I have to pull ovrr to the side and turn off my car for a few seconds and turn it back on. But then when i stop at another light it does it all over again. My CEL & TAC OFF lights are on. The CEL codes say i need both knock and crank sensors along with some part to do with emissions. Idk if any of that is affiliated with the car not engaging OD.
I've had so many random issues with this car that i haven't enjoyed it.
Probably two separate issues based on my experiences with both items:
Had the trac off/CEL and that was cured by replacing emissions air/fuel sensor part 234 9009. These sensors will go on a 16 year old car, so I consider that to be more maintenance than repair, but they can be a pain in the butt to have to go and do.
Recently car wouldn't shift in OD until after 15 minutes of highway driving from a cold start and that seemed to have gone away after dropping trans pan, replacing filter and fluids (first time I've had that done since I've owned the car for the last 10 years). I can't say that that is a permanent fix yet, but the problem has been clear for a couple weeks for me so far. You might have a different issue however since it sounds like yours doesn't shift into OD at all.