22re o2 Sensor

[Co-Man-Che]

I bought a 1991 Toyota pickup with the check engine light on. When I got it home and pulled the codes it read codes 21 and 25. One of which is for the o2 sensor and the other was a lean fuel mixture code. After checking out the wiring for breakage, my next step is to replace the o2 sensor. I have a good used one in my garage but it is for a later model truck. They look the same but the plugs are different.

So here's my question, can I splice the old plug on to the newer sensor? It seems that Toyota must have the changed the plug for a good reason so you cant interchange the sensors but when a new sensor costs $200 from the dealership, I want to explore my options first.

 

[Zoediak]

i would just go to some place.. like rock auto and order two new sensor... (upstream and downstream) that work with that vehicle..

they honestly are not that expensive..

i just got done replacing two of them and was into it less than $100 total...

heck.. the most expensive one on there for a '91 yota pickup is a bosh for $115

http://www.rockauto.com


if you don't need it right now, it doesn't hurt to look..

 

[WA-Wheeler]

replace it.....but not at the dealership.......

 

[super samurai]

no, cant innerchange. one is a big grey wire and the other is a 4 wirr. and because of the bad o2 is why you are getting the lean code.
when I stand alone wire a 22re I tell them they need to hook up o2 or it will lean your rig out over time more and more.

 

[Co-Man-Che]

no, cant innerchange. one is a big grey wire and the other is a 4 wirr. and because of the bad o2 is why you are getting the lean code.
when I stand alone wire a 22re I tell them they need to hook up o2 or it will lean your rig out over time more and more.

They are actually both 4-wire setups (2 black, one white, one blue).

I went ahead and spliced the old plug onto the newer sensor, installed it, cleared the codes and started the truck but still got the same codes. So basicly my not-so-scientific test is inconclusive. Looks like I will just buy a new OE type sensor.

 

[zukkev]

They are actually both 4-wire setups (2 black, one white, one blue).

I went ahead and spliced the old plug onto the newer sensor, installed it, cleared the codes and started the truck but still got the same codes. So basicly my not-so-scientific test is inconclusive. Looks like I will just buy a new OE type sensor.

Before shelling out the dough on a new oe sensor (which Bosch will work juuuust fine in its place for much less as stated earlier...), check to be sure the wiring to it is intact...make sure you have power at the heater power circuit at the plug, and also a good ground on the ground circuit...I can't tell you how many of these trucks I have found the wires melted on the exhaust, or rubbed thru by a bracket or something along the circuit, causing a short...

 

[Co-Man-Che]

Before shelling out the dough on a new oe sensor (which Bosch will work juuuust fine in its place for much less as stated earlier...), check to be sure the wiring to it is intact...make sure you have power at the heater power circuit at the plug, and also a good ground on the ground circuit...I can't tell you how many of these trucks I have found the wires melted on the exhaust, or rubbed thru by a bracket or something along the circuit, causing a short...

The wires had been burned on the exhaust and repaired poorly by the previous owner so I redid the repair. I will try what you said and check for power at the plug on the heater circuit as well as the ground circuit, maybe my repair isn't as good as I thought or there is damage elsewhere.

When repairing the shielded wire, I bundled the outer shielding strands, spliced them and heat shrinked them separately from the inner wire. Is this an appropriate fix or is there a better way of doing it?

 

[zukkev]

Yeah, that's how I do it too...The shielding around the signal wire is just there to protect from counter EMF interference by other circuits near it, and that far down, there is not any other circuit near it...make sure you have good continuity between the shielding and ground, that your power is good (could have blown a fuse when it melted), and that the ground wire itself for the heater is good...May also have killed the signal or signal return circuit in the ecm when it shorted too...can't remember the voltage spec there, but 5V seems to stick...

 

[Co-Man-Che]

Yeah, that's how I do it too...The shielding around the signal wire is just there to protect from counter EMF interference by other circuits near it, and that far down, there is not any other circuit near it...make sure you have good continuity between the shielding and ground, that your power is good (could have blown a fuse when it melted), and that the ground wire itself for the heater is good...May also have killed the signal or signal return circuit in the ecm when it shorted too...can't remember the voltage spec there, but 5V seems to stick...

I checked all the fuses in the kick panel and under the hood, they all checked out. With the truck running I was getting 15v to the white wire with the red stripe (I assume that is the heater circuit). The brown wire and the shielding wires had continuity to ground, the black (signal wire) had 20 ohms resistance (no voltage) and the pink wire had nothing. Sorry I'm referring to colors instead of circuits but my Factory Service Manual hookup hasn't come through for me yet.

So, should the pink wire have the return signal of 5v on it?