My ES300 has a knock/ping that i can't get rid of.

It pings under higher RPMs, so when accelerating up the slightest hill or when speeding up, but not under low acceleration. It has new plugs (knocking started long before plug change), new knock sensor and o2 sensors. (I had a check engine light that kept coming on and the mechanic kept wanting to replace the o2 sensors over again calling them defective instead of trying to figure out what the real problem was) so I ended up cleaning out the MAF a few months ago and clearing the codes, CE light never came back on again. That lessened the knocking, but didn't remove it completely, and now its back to where it was again. I'll could clean out the MAF again, but it never completely removed the knocking - any other ideas?

 

how long has this been going on?

what type of fuel are you using?

 

As long as i can remember. I've owned the vehicle for a little over a year, and i don't remember if it was knocking when i first bought it. I only use premium fuel, try to use only chevron.

also, I seafoamed the gas tank awhile back, didn't make any difference. Mechanic added something to the tank last time he changed the o2 sensors and knock sensor - i don't know if it was a fuel injection cleaner or what.