While symptom is similar to what other have described with throttle position sensor problem, it's quite different.

Going at freeway speeds. Suddenly throttle is responseless. Not "hesitates" or low power....zero engine response from any throttle movement. Engine continues to idle just fine. It's done this before and I could kill engine (while still moving or stopped) and restart and throttle would return. This time I can restart engine and it idles just fine, but it's like the gas peddle is disconnected. tried disconnecting battery for a sec, but didn't help (only thing I could think of)..Also cant see codes until tomorrow.

 

Fairly sure you'll have a code thrown.

 

Even the basic scanners that you'll use to pull the codes can usually show you live data that will include the throttle position sensor. I don't know for sure about the G35 but my family's Murano will show you both pedal sensor positions, the commanded throttle position and the actual measured throttle position and if they don't correlate properly because something is wrong with one of them, it will throw a code. I can hook it up to my G the next time I drive it and see what data PIDs are available. Seems like something you should be able to monitor would help point you at something. If the pedal sensor just sees no input because it's defective, unplugged or broken wire etc., the car thinks he's just not on the gas right? If that's the case, maybe no code?

 

If it's not working properly it won't be sending the correct data and thus a code will be thrown.

The APP is two switches, they send inverse voltage, first switch is 1vdc-5vdc, second is the inverse 5vdc-1vdc.

If the switch is unplugged it's an open circuit, the car knows. If one switch fails the car knows since it's expecting two inverse voltage signals.

Actual throttle position work the same way, two signals, inverse from one another. It's a sort of "checks and balances" so the car knows everything is actually hooked up and running correctly.

 

I said" I couldnt see any codes until tomorrow".
I didnt say it wasnt showing any. I didn't have access to a reader until the next day.
Reading comprehention, people!
That said......
Turns out it was the throttle body itself.
Lets talk about that Concept Z was the retailer for the hitachi 75 mm TB with parts to make it fit. Supposed to be plug and play.
nope. Not if you have an aftermarket ecu. But eventually everything worked for about 3 months. Then the above happened. Guy that built my car said it was the new TB. Because I bought it and had the shop install, labor isnt covered. But Concept z said I have to send it to Hitachi and theyll determine if that is the problem and fix, not replace it. I said that could take months. I said BS said a new one out. In the end, my guy overnighted the TB to Concept z and sending out a new one when they get it.
Moral of the story? When having a shop install a part, let them buy it, otherwise you have to deal with part of the headache of getting a replacment if needed.

 

Nice attitude Steve-o..... I believe both Cleric and I read and understood your question perfectly well. We were discussing if a code or live data would be the surest way to debug your issue whenever you were able to connect to it.
That said.....
Glad you got your car working. It sounds really racy....

 

Rereading the post, it still sound like they're trying say a code *will* show, but that's the problem with email and text. Misunderstandings are easy without voice inflections and body language.

Wish it was "racy", but with her fat ***, without some forced induction, it feels slow as ****/

 

Indeed misunderstandings are easy. But it seems like you understood as Cleric was confident a code "will" show....... tomorrow when you try to pull any (as stated). Because of this I generally try to give people the benefit of the doubt rather than come down on them right away especially if they're trying to help me. But this isn't a grammar or etiquette forum..... Did a code end up showing up? With an aftermarket ecu and aftermarket throttle body I wonder if everything is going to measure and report the same exact way the oem modules would...??? And throw the same codes when something is wrong.