Help with O2 Sensor (I did a search) (1 Viewer)

[GabeJ]

I have a 1991 FJ that's thrown a code #28. "Number 2 O2 Sensor." Denso has two part numbers. I guess one is front and one is rear. Can somebody make it clear to a dummy (me) which one I need? A part number would help, too

Also, my radiator gets very hot when the car runs. I mean like hot to the touch twenty minutes after I've stopped running the rig. The fan is spinning, so I was wondering what I should be looking to do. Should I order a new radiator cap to make sure fluid is moving out like it should. I'm in over my head, so any help is appreciated.

Thank you.

 

[GabeJ]

Anybody? Thanks for the help.

 

[Tally FJ80]

The two part #'s are for the two O2 sensors the 3fe has. It has one in front of each catalytic converter. I changed both of mine when it threw the code. I'd flush the radiator after you run some radiator clean in it for a while then see what it does. Good luck.

 

[Explorer4Hire]

Get both. The other one will be right behind. Your going to have to clean those surfaces good too, might as well handle it for both while your down there.

 

[red mud fj]

Few years back the orignial down pipes correded through around the O2 sensor so to just get by I remove that section of pipe before the catalytic converter, ran that way for a year or so before installing new down pipes. Gas mileage was much better with the O2 sensor default setting running!
Connecting wire length is the only differenct I noticed between the two O2 sensors.

 

[GabeJ]

Well, the FJ just got a whole new exhaust, so I'm not too excited about buying both right now. You're saying that it doesn't matter which one I order? It seems odd that the code describes them as "No. 1 and No 2," but the part is labeled left and right. Grrr.

 

[dallen341]

I'll bet number 1 services front 3 cylinders.

 

[arcteryx]

See #1 and #2 below, that should answer your question. I would replace both though.

Rads are going to be hot, that is why you have to wait to open the cap after they are run. Even after an hour or two, engines will still be hot. I don't see how changing the cap will do anything, that is more if you are loosing coolant.

You should perform a proper flush. Do this Gooch's Radiator/Engine Backflush Procedure and Coolant Information - Ford Truck Enthusiasts Forums It is written for Fords but is applicable to all vehicles. I have used that procedure with great success on my Ford and Toyotas, and is the only want to ensure that all of your coolant is removed as well as to dislodge any blockages. I would do this ASAP as the last thing you want is a cracked head which could occur with high heat. That is $$$$

 

[decoco]

I am a wrench dummy, but I agree on the cooling issue, there's something not right, and a flush may fix or reveal the culprit...
to re-fill MAY (or should) want to use Toyota Green or Red, start with a search.


you're getting an issue with the sensor, if you're going to replace 1, replace both, and set it and forget it...

Why a radiator cap?!

 

[GabeJ]

Thank you guys so much for the help. I was thinking radiator cap because it has the valve to the overflow reservoir, so it seemed like it might be affecting the circulation of the fluid. I'll keep this thread up to speed with what I find out.
Gabe

 

[decoco]

please do!