ok update after thouroughly exhausting all possabilities we went to lexus only repair ,well they were as stumped as I ,they even had a guy from the lexus dealership come over to assist, we all used the guide i found here on code, and code retriveal and clearing, well the lexus guy was able to go one level further, after we cleared the iac and, even though i had cked the MAF mass air flow, it looked like just one of the sensors in the mass airflow was not working IE the sensor was working but only partially then beyond a failed point, the sc400 ecu has the ability to ignor the problem to continue running, other codes that come on later are due to inaccuracy of the current item whatever it may be in this case the mass air flow sensor sending out inaccurate data, therefore intermitten light on light off that kept pointing us back to the IAC which is fine, so final decison was to replace the MAF, well a new one is 1338.00 including the aluminum throttle body piece it sits in ,which is rediculous, after searching through endless shops i found one 125.00 delivered with housing, well it arrived i cleared the system started the car and , damn light still on, ok we are really confused now right,, but hold on... i say well hell no worries ill take it out we will try again allthought reving the engine having it in neutral and all of these other factors produced no change, driving it did!! it seem to have plenty of fuel and acts like it is learning to take all the air allthough it is still in a state of education we will call it ,the light has remained off the the amount of fuel it is dumping is high as mentioned i think it is still learing to balance the air fuerl mixture but a very serious change maby to much so, but that is the latest in injen upgrades also note:: i dont have the stock injen i got the injen pro tuned dyno tested CYBORG system supposedly the most advanced one for the sc400 as im told thus making breakl in longer but perhaps more than i expected for a highquality cold air intake, more to follow as it becomes avalible and hope this helps someone ..i do love the look and power when consistant but be careful what you wish for my main hope is that im not prematurely taking years off the cars engine life with this hi performance enhancement. all though seeming simple it has gone way beyond what i expected for a mild bolt on perfomance item..