Hi thought i would offer some feed back here for you,i used to work for lexus/toyota up to 6 weeks ago.There are some issues with the 5th injector and all injectors for that matter with the 220d.the engine is from the avensis T180 to start with,where it had small problems with the e.g.r system and water consumption.when they fitted it to the is220 they made it rear wheel drive and re-maped the e.c.u to allow for better driving.this caused the car to over fuel on short runs cloging up the e.g.r even faster and causing ruff idle and poor m.p.g(the car was never great on m.p.g before).the 5th injector is for cold start and extra fuel for high throttle response(very basic discription here)the problem was it was staying in to long and over fueling(this is the e.c.u re-flash you are talking about to aid the problem).the over fuelng was cloging up the injectors making the whole problem worse.Lexus have made new injectors now with a differnt spray nossile and coating to ease the issue.there have been a few cars that have blown head gaskets due to these problems.
I hope that shines a bit of light on the subject for you all?
Thanks for all these informations ! I was told about a new version of the fifth injector, but not for the 4 other ones ! Can you tell me please when this modification of these 4 injectors was done ?