99 Lexus ES300 issues
After a tune up, R&R spark plugs, air filter, cleaned MAP sensor, coolant
hose fix, PCV valve cleaned...everything went extremely well. While getting a
very smooth running engine up to operating temp to check for any leaks (ran
AC on full, then heater to make sure coolant levels were full and engine at
normal temp) the engine went from smooth idle to surging slightly RPM up
and down and running a bit rough. Check engine Light flashed so checked
codes and found random misfire and a code for cylinders 2, 4 & 6. (front
bank) Checked all vacuum connections, electrical & anything else I might
Have disturbed during the tune up. I'm guessing there is something now
going on that is affecting only the front cylinder bank but I'm not sure where
to look as the back bank (1,3,& 5) seem to be fine (no codes anyway!) Any
incite on what to run down first as I feel there has been a change in fuel mix
due to a vacuum leak maybe to the front bank? Appreciate any response or
suggestions on where to proceed next!