I found the solution to the problem and did a write up on it. You can view it here. https://www.clublexus.com/forums/gs-...misfiring.html

It looks like the SeaFoam did the trick for yours, however If I were you since you just bought the car, I would take a look at the Throttle Body and the Oil Control valve as mentioned in my write up, and clean them both.

 

its a first gen gs300 though... lol
im having this issue with my car right now.. i had changed ECUs
sensors etc were all changed n check engine light was still throwing O2 sensor codes.....


replaced ecu n NO check engine light but when checking for codes, check engine light blinks constantly......

 

facing same problem... Anyone with a solution for it? For ls400 98 model

 

LEXUS(DTC)_985392572000_20180219124342.pdf

please hellppp

 

I had the same problem. Obd scanners read multiple misfires, O2 sensors, cats were shot. I just did a combination of idling & driving with seafoam added until all the bad gas burnt out (didn't have a siphon). Problem still exist. Saw a trick on YouTube about pouring lacquer thinner in your tank. So then added 1 qt of lacquer thinner in the tank & filled to 1/4th tank. Then I drove around on that mixture until I burned all what was in my tank was out. During the process the hesitant stopped & it started to drive back to normal. everything on the scanner now saying its fine, no error codes. Refilled & I'm back to normal like nothing happened. Lacquer thinner has more cleaning agents than gas treatments. & is excellent at absorbing water.

 

Finally it worked for me, after i changed my fuel injectors. My cars use to jerk when i accelerated and had misfiring.. Since i changed my fuel injector its working all fine.