2ZR Turbo Yaris

[06YarisRS]

Originally Posted by CrankyOldMan

In a perfect world, yes, but only if everything else in the vehicle was able to do that. There's probably a closer ground that's used by the ECU. You'd want to try and use that instead since you're connecting to that part of the electrical system. The other thing you risk doing by running a separate conductor back to the battery is called a ground loop. Basically you're making a new path for electrons to flow between the two ground reference points and causing one of them to be above zero. Here's an article with some examples of automotive grounds.

I should have a copy at home but might not have time to review it tonight.

Ah, yes, ground loop. I am a bit familiar with that having installed a few of my own car stereos.

I did get a hint from the AEM guys. They feel that one of the wires on the TPS is a signal ground. They also said that I do not need to hook up the two 02 sensors and suggested that the most simple setups seem to be the least problematic and most stable.

I also sent my questions, along with diagrams to the turbokits.com guys and Jesse, the lead tech, is sending them to the guys that make the Plug and Play harnesses. So, hopefully I will have definitive answers soon. If you do get a chance to review your diagrams, I'd be thankful, but only if it's not, in any way, an inconvenience for you. I really appreciate the thoughtful and informative responses that you've given so far.