'01 Lexus ES300

142382 miles

Bought used month and a half ago

Have had trans professionally rebuilt due to previous owner frying the solenoids, sun gear and torque converter. 

PO304 #4 misfire

Dear Scotty,

My question: Can a recently tuned car have a high idle? Seeing it at 1000 to 1100 RPM.  I've replaced MAF, vacuum valve switch (repaired broken hoses also - stem of unit had broken off inside hose, I found it had been glued on in the past by a lazy person - it took me ten minutes to repair it) and have had throttle body cleaned out. Replaced air filter. Replaced vacuum purge on the front rail. Loose hose connected to nothing on one of the valve stems, stem had busted off. Also replaced vvt switches and knock sensors. Dropped the oil and filter twice now. Car now is running much smoother than it was and no more detectable vacuum leaks. My hunch is now dirty injector or injectors. 

Can you offer any insight here? When I pulled the neg terminal to do the work, when reconnected the car initially stalled and sputtered but then once I opened the throttle up and let it settle, it ran very well just high idle. 

Thanks,

LandRoverDan