P0171 and p2195 I'm stuck and don't know

Based on the AFR voltage fuel trims and downstream sensor voltage it is so lean that it is not in fuel control so I'd definitely look at fuel pressure next.

 

A/F is pegged High
O2 is pegged Low

Strange?

 

Ikr

 

Ya I'm thinking I've got a fuel issue now for sure.

 

Toyota didn’t make it easy. You need a T type adapter.
https://www.tacomaworld.com/threads/not-enough-fuel-help-update.681264/page-2#post-24029864

 

Maybe that's why they titled the section "FU."

 

Big facts lol

 

So when I replaced the air fuel sensor recently I found that the connector plug on the harness was all burnt up from an exhaust leak I just fixed to. (Bought the truck like this and then the engine light and all the issues came soon as I own it) anyway I put a denso 4 wire upstream sensor on with the 2 black wires and a blue and a white. I'm just curious to know if anyone else has a similar Toyota what are the factory wiring harness wire locations in correspondence with the plug? The harness side has a red a white a lavender and a pink. To my understanding and the way I've wired it is the white wire from the factory harness is showing 12v so I put it on top pin#2 . I believe which is one of the black wires on the denso sensor and then the red wire which isn't showing any voltage or anything on pin#1 which is the other black wire. Then I put the pink wire on pin 3 which is the blue wire on the sensor side and then the lavender wire from harness side to pin 4 which is the white wire on sensor side.??? To my knowledge this is right right?

Also is it normal for the red wire from the truck harness side to not show any thing as far as voltage or ground or resistance goes?

 

That may be your problem.
I know at some point I found a chart with diagrams.
I’ll try and dig it back up. With the help of @Dm93 maybe we can figure out what +/- to ECM is.

 

I jumped over to the Denso website and plugged in the data for a 2010 w/2.7
I got this part number and this image. If the image is correct, we might get some where.
https://www.densoautoparts.com/find-my-part.aspx#searchResults

OEM pin location


IMPORTANT - These are for O2 sensor colors. But I never have seen a chart or diagram for the A/F sensor. My assumption is, they are universal.



And if you wonder how I found this so fast.
Let’s just say I’ve been here before with another member.
https://www.tacomaworld.com/threads/2005-downstream-o2-sensor-wiring.710655/

 

AFR sensors operate off current, the PCM displays it as a voltage. If I recall correctly 2.8v is stoich (14.7 to 1) higher voltage is lean, lower voltage is rich.

 

You’d be correct going by the logic of the P2195 diagnostic

P2195 indicates an A/F stuck lean


If the A/F sensor voltage output is less than 2.8 V (very rich condition) for 10 seconds, despite the rear HO2 sensor voltage output being less than 0.60 V, the ECM sets DTC P2196. Alternatively, if the A/F sensor voltage output is more than 3.8 V (very lean condition) for 10 seconds, despite the rear HO2 sensor voltage output being 0.15 V or more, DTC P2195 is set.

If the A/F sensor output is 3.6 mA or more for more than 3 seconds of cumulative time, the ECM interprets this as a malfunction in the A/F sensor and sets DTC P2195 (high-side stuck). If the A/F sensor output is 1.0 mA or less for more than 3 seconds of cumulative time, the ECM sets DTC P2196 (low-side stuck)

 

Just looked at the AFR voltage chart, looks like 14.7 is about 3.2v

 

So according to the color code and chart there I apparently have the wires wrong then right because signal+ would be my 12v white wire from the factory harness side and it should go to the blue wire on the denso sensor side and the heater+ which is pink should go to prong 3? On the sensor plug? I know when I last checked the voltage and resistance the two black wires on the sensor plugged beeped for continuity when touched and the white wire with 12v from the factory harness is connected to one and the red wire with no voltage is connected to the other so if those 2 black wires on the sensor are the heater wires then shouldn't I connect the pink and blue wires from the truck side wiring harness that both read a voltage that's almost the same I think the pink wire is showing 8 and the blue has 7 those should go to the heater wires and the other two bigger wires white 12v+ and red... 0 to the other two prongs?