Hi I have a 92 q45 with TCS and I'm going to do a fuel injector clean via a vacuum line on the throttle body. I was wondering can both of the lines on the throttle body (one running to under the plenum and the other leading to the side of the engine) can both be used for a fuel injector clean? and what is the difference between the two ports on the throttle body?

That proceedure won't clean the fuel injectors! Rail flush or BG44K in tank.