Thirsty Avalon

[rayt32]

When i purchase my 2001 CSX Avalon three years ago w/ 136000ks on it, the average fuel consumption on the computer reads 11.5 liters /100 km. It suddenly becomes thirsty when the transmission started to slip which is understandable. When it undergoes a transmission transplant (from a wreck 2004 VXI) and still slipping and i was able to fix the slipping problem ( pour a small pouch of Lubeguard anti shudder fix), the computer reads 15.5 liter/100km. I also do manual computation in every fuel fill up and it comes close to the computer reading.

I connect an OBD II scanner ,there is no indicated fault codes, countercheck it by bridging TC- E1 of the Data link connector found on the right hand side beside the strut tower (DIAGNOSIS) no fault either. The car now has 161,000Ks on the odometer and been doing research about the life expectancy of the O2 sensor on Avalon which is 250,000ks.

I remove the front O2 sensor and had taken note of the part number (p# 89465-33160) and visited different O2 sensor manufacturers website. I open up the website of Rockauto.com and do a part search for 1997-1999 Avalon ( American Variant of the 2000-2002 Australian MCX10R) and search under Emission and found out that Standard Motor Products O2 sensor w/ part number SG368 upstream carries the parts interchange on our Australian Avalon. By the way i had experience using the Standard Motor Products O2 sensor on my 1991 Ford Telstar which i bought here in Brisbane for $80.

I search on Ebay (US) and found $30 (discounted) a piece direct fit and bought 2 plus $15 freight. Ebay Australia and EFI supplier could only provide generic in which you have to cut the old sensor wire and make use of the connector.

The sensors arrive yesterday and I fit it today and have a run on it. The computer reads 25 liters/100km at first and while the ECU is relaearning itself while i was driving in the highway the computer reading is becoming less and less until it got stuck to 10.8liters/100km.

Just imagine i was losing around 4.8 liters/100 km because my O2 sensor is becoming Lazy.

The front sensor is a straightforward replacement, while the rear is quite hard because of the space. If you need advice or question, post it in this thread and am willing to reply asap.

Thanks for reading,

rayt32

[rayt32]

hello guys i have posted the old lazy oxygen sensor picture and the box containing the new sensor .

[leep124]

Hi Rayt32,

my import estima has I think the same 3ltr engine as the Avalon. I recall reading on the web that these v6s have issues with the oxygen sensor. I am getting 14 Lyra/100kms.

Did you replace both front and back to get your good result? Also did you have the reset the computer at all for the car to learn your driving habits?

any help would be appreciated.

regards David

[Andrew357]

Replace both o2 sensors at the same time then reset the ecu. Let the ECU relearn the driving patterns.

[Teri Tere]

So the Avalon only has one pre-cat sensor and one post? The one post is under the car near the firewall right?