Oxygen sensors - part numbers (all years) and replacement

[rowemjr]

I never reported back:
Both sensors are in. A new cat is in. All went well.
I have yet to check the egr. We just welded on a mount for the rear sensor and plugged it in.

Is the rear mount just a universal bung modified to fit or is there actually one available that works without any modifications?

[cpginkpt]

88 4WD

replacing my catalytic and looking at Rock auto. Bosal with included O2 sensor <> Walker + add a sensor.

Any reason to go with one or the other? Also what's the deal with the O2 sensor pricing/"features" assuming I go with the Walker - why are some sensors $23 and other $70++?

Thanks.

[Burntboot]

Pre 88 vans didn't have the rear sensor, Walker makes jigsaw puzzle exhaust, so ordering the correct over axle portion (with or w/o o2) is how they got around one system fitting all years.

Bosal 2 made complete rear sections (->87MY,88MY->)
But probably not an issue as I believe the Bosal stuff is long gone, the Walker may also be in the same boat.

Rock Auto pricing can be confusing because in a lot of cases they are dealing with odd lots and cast-offs and inventory liquidations.... because of that, pricing isn't always the deciding factor (on quality) over there.

I have had really good luck with NTK and Denso sensors
On the other hand, I will never install another Bosch o2

[Burntboot]

And if for some reason you have actually found a real live Bosal exhaust, that is the way to go.

The fewer the connections, the fewer the leaks and the Bosal unit aligns nicely on the hangers.

[cpginkpt]

Thanks for the tips, so I am going Rock Auto with the Bosal Cat since they say they have it in stock...

...BUT the NTK lists both an upstream and downstream sensor.

My current setup only has 1 sensor (?) so which should i get (or both?)

[Burntboot]

Your van has 2 Oxy sensors
One up at the manifold, the other just behind the cat.
In terms of up vs down, the one after the cat is "downstream"

[cpginkpt]

awesome. Thank you!

[Flecker]

Pre 88 vans didn't have the rear sensor

I have had really good luck with NTK and Denso sensors
On the other hand, I will never install another Bosch o2

I will second the Denso O2 sensor. Direct fit and quality product... for O2 sensors I only ever used the Toyota/ Denso application and has always worked flawlessly.

Question On the later vans with two O2 sensors... are they run in tandum, or does the ECU get two signals to it?

[cpginkpt]

Interestingly the Bosal cat actually says “w/O2 sensor” in description.

Guess I need to clarify that with Rock before I order the Denso O2...hmmm

[JDM VANMAN]

Here’s the downstream sensor out of a 4WD auto-








JDM

[Burntboot]

Flec - Question On the later vans with two O2 sensors... are they run in tandum, or does the ECU get two signals to it?

Code 27 - sub-oxygen sensor signal, open or shorted

[HI_Beach_Van]

My July 1989 van is showing the 21 code. the PDF from another thread ( https://www.toyotavantech.com/forum/...gons-all-years ) shows it as either the Upstream or the downstream. How do I determine which sensor needs replacing?..I would prefer not to have to change them both out unless it is necesary.



Thanks for the help!

[llamavan]

The upstream sensor by far gets the most abuse (heat, carbon), so replace that first, clear the code and drive.

Gwen

[iq_artwork]

Hello everyone,

I ran my codes today and I got the code #5 (oxygen sensor signal). So I'm planing to replace it in my van.
I have heard and read some vans have 2 sensors and some ones one senor. I'm guessing my old generation '84 van has one sensor.

https://www.youtube.com/watch?v=8UNkX1RSUDo

I found via this website, Tim shared here this denso sensor. Is this the right part?

https://www.sparkplugs.com/product.aspx?zpid=17828

Thank you!

[timsrv]

Yes, that one should do the job.

[iq_artwork]

Thank you Tim for your reply! I have ordered the sensor and it's on the way.

Today I checked under my Van and I noticed my 02 sensor is broken and looks like always was broken. But I have never had a check light on and off when i was driving.

A month ago, I cleaned my Throttle Body, replaced and adjusted a new TPS, replaced all my vacuum hoses and my mechanic replaced the fuel injectors.
I noticed the van is ruining way better, faster and smoother.

So I was wondering if all these changes have to do with it?

[timsrv]

Every little bit helps. The van ECU has a "default" mode that it goes into when it can't see data from sensors. Because running too lean can damage the engine, the default mode makes it run rich. Rich running engines get poor fuel economy, run dirty and do not perform well. If left to run rich too long, other bad things happen like plugged up cat converters and fowled spark plugs. By repairing/replacing you are giving the ECU back the basic tools it needs to do it's job correctly. I suspect you will notice a MAJOR improvement in power and fuel economy when you get a good o2 sensor in there. Tim

[iq_artwork]

Amazing! Thanks again Tim!

[LGW]

I have a 1991 Townace (YR30 5013276) 3y engine. The original oxygen sensor number is #89465-19066. Does anyone know a comparable sensor I can use?