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Can anyone explain why the power wire of efi fuel pumps and O2 sensors require shielding - the actual wire running inside braided stainless? steel sheath.


Have all those that have convetered a non efi car to efi observed these requirements or just gone ahead and wired oblivious to the need? Any bad experiences?

The o2 sensor operates on a low dynamic range (0.1 to 0.9v) and is thus sensitive to interference. The air flow meter, knock sensor, throttle sensor and crank angle sensor are usually shielded for the same reason.

The fuel pump on the other hand is shielded so that it doesnt inject its own interference (DC motors produce quite a lot of electrical noise) into surrounding wires.

When i converted my car, i used the whole efi loom. I chose to do it this way because i wanted the wiring for the electric windows, locks ect.