Knock Sensor Light Effecting Transmission Shift

[wpvaughan]

I have a new to me 1999 RX300 with 204000 miles on it. The check engine light comes on (auto zone tells me it is the Knock Sensor on both banks) and tells the transmission not to shift to overdrive. The mechanic that has maintained the car for the last 9 years is the one that has replaced the sensors and i have seen the maintenance log and it is complete. He is telling us that it is the Octaine and the we should go to Mid Grade. We did that and the light came on and we visited Auto Zone. Do we need to go to High Test or do you have other recommendations.

Thanks,

Bill

[hotrodgirl70ss]

My 2000 rx 300 does the same thing and I have replaced both knock sensors recently. My solution was to buy a cheap OBII scan tool so you can clear the codes yourself. Once they are cleared it will shift again. Also if you turn the car off then back on it should shift also.

[lenore]

Sometimes the knock sensors wire harness could be the culprit. The insulation becomes brittle and maybe is shorting on the intake manifold. If the sensors where replaced than maybe the wiring is rubbing somewhere.

[now50]

Thanks I was changing my Valve cover gaskets after 240K so I thought to change everything else like knock sensors, knock sensor wire, water by-pass hose plugs, and coils I did not have any codes but did notice the engine idle go up once three weeks or so ago. i thought it was hesitating also but had it so long and think that any noise is a problem I buttoned every thing back up now I have a code 0325 bank 1 knock sensor any advice and how long can I drive be changing I won't get to the issue of for three weeks does anybody know the cause and effect if I wait and could it be a fuel problem or throttle body position sensor