No Overdrive, Knock Sensor Related ?

[provis]

I have a 99 es300 with 120,000 miles. Every couple of days the check engine light turns on (P0330-knock sensor) and the car fails to go into overdrive. Then the check engine light goes off and everything seems fine. Sometimes when I'm at a stop sign, the car has trouble accelerating, until I keep pushing the gas pedal harder, eventually it picks up and goes. Just before the check engine light goes on I hear a rattling of metal that only happens when I accelerate.

Any ideas? Will changing the knock sensors help? If so, how are the knock sensors related?

My understanding so far (please correct me if I'm wrong), is that the failure of the car to go into overdrive is a "limp" mode or a protective mode the car gets put into when there is a problem. Again, I'm not sure how the knock sensor is related.

Things I've done so far that have not helped:

tried using name brand gas

tried techron additive

went under the car to see if my heat shield was loose, it wasn't

Thanks for your help....have been confused about this for some time.

[George_Jetson]

P033 code will place the ecm into a limp mode, with max !Removed! of timming. Which explains sluggish acceration. I don't if that locks out the overdrive, but that's reasonable assumtion. Do you hear the rattling everytime you accelerate? Or only when you get the check engine light? The knock sensors are pizo electic crystals (crystals that generate a electical current when struck). A bad rattle could be picked up as knocking. Find out what is rattling.