O2 sensor ? at Dealer Now and Antifreeze specs?

[dcg129]

Very impressed with the answers I have seen in this forum. My 95 Avalon is in the dealer, as I type, for the first time in 6 years of ownership, other than once for a timing belt change at 112K. At 149k check engine light went on with an O2 sensor code saying that the heater core inside the O2 sensor on the exaust was not working. Changed once and came back on. MY Mechanic with 50 years of experience said 50% of O2 sensor don't work properly and changed it. It came back on. Unusual for him to say , "take it to the dealer." So it is there now. Any suggestions? My Mechanic said, "on american cars it is the Catalyic converter that goes bad sometimes."
Have any of you had similar problems.

Finally, I read that Toyota Red Antifreeze is just the regular Green Antifreeze died Red? Can I use the regular Green? What ar your thoughts

[toyomoho]

The codes are specific as to which sensor is bad. Make sure the right sensor was replaced.

If a converter, typically the P0420 code would appear, or the car would fail emissions with high NOx or the engine run sluggish due to a possible plugged converter.

Odds are the issue is a sensor which fail much more often the converter.

Toyota's can have issues with some brands of sensors such as Bosch, suggest using Denso or Toyota brand.

Toyota coolant is silicate and borate free. If changing to another brand of coolant flush out the system before replacing. See link below for info on coolants.

http://www.popularmechanics.com/how_...e/1272436.html

[SteveBa]

I just went through some radiator changes and did a lot of reading concerning antifreezes. Always thought it did not matter, but there is a difference. They are not all the same. The variables are type of block, head and radiator. Personally I would stay with the manufacturers recommendation and you will get many opinions on this. It may cost you $20 for the gallon, but that's all you will need. And use distilled water only. Just my opinion.

[toyomoho]

I am using Zerex G0-5. Folks have complained about Dexcool.