gt2av8

Hi all,

I"ve bee doing some work on a Sequoia for a family that I'm friends with. Long story short, it had all 4 O2 sensors replaced last fall, yet throws heater circuit malfunctions for all. Well, the report I got is that the shop said they "couldn't get them wired right." Last week when I did brakes on it, I crawled around to find that they used all Bosch sensors, which I get the idea Toyotas don't play well with. So, there's my answer. Here's my problem...

The wiring for the bank 2/sensor 2 they chopped out all the way from the sensor up to the (inch and half or so thick) wire wrap at the top rear of the engine. They replaced the inbetween wire with 4 identical black wires. So, I have no idea how to match the colors for the new sensor (I'm replacing all 4 with OEM Denso sensors).

From what I've been able to tell, the wiring harness that would have been there would have had...
Blue - signal
White - heater
Brown - heater
Gray - Ground

So, here's what the approx 3 inches of wire coming from the wrapped section are (which are then spliced to the blacks and spliced again to the sensor)...
Color with color stripe (unsure of color)
Color with color stripe (unsure of color)
An off white/cream/yellowish funky color
White - and this one is a heavier gauge than the others.

Any ideas?

If I can't get the color matches, I could somehow test them with a multimeter, right? If the ECU is coding them all w/ heater circuit fault though, will it try to use them or are they cut off? (I don't have a scanner to reset, and if I go to the store to reset it, it'll have the codes again by the time I get back with it).

Thanks, all!