Damn dude sorry to hear about the problem that your Z is having... well my Z like Pedro said... at the moment when the problem starts have around 20k miles. Saying that i see that you clean your throttles and a few things more. Well one of the things that i dont see that you do is calibrating them... Thats one of the things that i think that resolve our problems... Cause the mechanic that work my car in Service told me that one of the throttles open 100% and the other 50% or least causing that the car go into limp mode and not accelerate like they have to do. After they do that i dont have any issue on my Z... The price for that labor i think is arround $40-$60 for each one but i dont remember the correct price. Check that and let us know if that work
