Alright my 2000 gs 300 keeps having some random issues. About once every couple of months my cel will pop codes 0300, 0301 random misfire and cylinder number 1 misfire, last time the positive on the battery was loose and after i tightened it up everything was fine again. It stumbled a few times this summer on the wife and the cel would come on and go off by itself. So I put new factory plugs in after the originals had 147,000mi on them new pcv valve, in tank fuel filter air filter cleaned mass air flow and I also cleaned the oil control filter giving it a complete tuneup. This stuff was long overdue so I figured I would eliminate these things. Now the other day its started its crap again same codes same misfire problem so I pull rhe front plug wire and ground it and sure enough there is plenty of spark. I then put it back together and know the car runs perfect again for twenty mins or so. I shut the car off and let it sit for an hour or so and restarted it and oddly enough the car runs perfect again. Maybe if it would just stay broke I could fix it but when ever I seem to try to dig deeper the problem goes away. Any help would be greatly appreciated thanks.

 

If you have spark, and you have air, it's fuel injector testing time. https://www.clublexus.com/forums/mai...injectors.html

 

I never had an injector randomly work and not work. any other car i've owned when they have gone out they stay out. I suppose next time it craps out I can try to check them.

 

What did the plugs look like when you pulled them? Did #1 look to be a problem?

 

Actually no believe or not they all seemed ok for 147,000mi. I wonder if my computer is giving out I just cant imagine an injector or a coil pack working or not working. I also checked all wiring and vacuum hoses too.