i removed the stock air intake tube that connects to the throttle body. and turned the butterfly manually through the cable and noticed it doesnt open all the way but when i turn it where the TPS goes (front) manually it opens all the way ... leads me to believe the mechanism inside the throttle body is shot... i dont know if its the ECM or the throttle body itlself

 

You did not find a problem. The cable is not going to make the throttle open 100%. It is only there as a fail safe for limp mode. It is designed so that if the electronic system fails, the last 10-15% of the pedal will engage the manual cable so you aren't stranded. Really sounds like you need to take this to the lexus dealer since the indy shop didn't know what they were doing.

 

If you are serious, i will come tonight with cash and pick it up.

 

I can tell you exactly what the problem is. Very common problem on the 80mm TB found in the SC/GS 400 cars. Its the accelerator position sensor. I have replaced it on at least 3 cars with the same symptoms as yours with 100% successful results so far. I think its around $250

 

i purchased and replaced that part 280 from my local lexus dealerand still nothing - removed it and installed my original one

 

if you removed the TPS sensor you have fubared the system already and you need to take it back to Lexus to have it reinstalled. You simply CANNOT reinstall the TPS once its been removed without a way to read it when it is reinstalled and get it back into stock spec readings again.

 

the tps was reinstalled to specwith a live data scanner paid 60 to get that done..

 

hey guys to update... i was able to get some of my cash tossed around back .. except on the tps $60 loss.
i took the car to the mechanic yesterday and today i went to check and i find the check engine light not on (good thing) and the accelerator responding as normal (good thing) but after a while the rpm would act up going up and down various times causing the car to do a burn out lol at a stop.

so now the mechanic is telling me i might as well just swap out the throttle body. and eliminate the problem as a whole.

found one at a junk yard for 150$ it should be delivered to the shop and i should have my car by monday.