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Nerys · 10-20-2010, 10:24 PM

tjts - I would have to say your diagnoses is incorrect. the O2 sensor is fine. In fact it was one of the first things I replaced. I installed a new O2 sensor and when nothing changed in 2000 miles I removed it and reinstalled the old sensor Still no change.

Are you seriously trying to tell me I have 10 bad O2 sensors and no codes ? the probability of that approaches zero.

in fact while getting 17-18mpg in the jeep it suddenly started getting 9-10mpg about 2 years ago. It was the O2 sensor. I replaced it mileage returned to 17-18mpg but never to its correct 22mpg unless I got E0

I had a similar problem in the VAN but in this case the "wire" leading to the O2 sensor came out of its stay and came into contact with the exhaust which promptly melted it.

Fuel economy off course tanks and it threw a code. I replaced the sensor and secured the pigtail better (the old twist lock thing that held it had become brittle)

Mileage returned to its E10 lower ratings ie 13mpg.

thats is 3 of my vehicles where I replaced the O2 sensor post ethanol. 2 needed it 1 did not. the 2 that needed it did NOT need it on ethanol. it failed POST ethanol for an unknown reason on the jeep and because of the melted plug on the van.

I DO now have a scope now. once I learn how to use it I will even be able to VERIFY that the O2 sensors are fine.

The minivan is OBDII and was checked both O2 sensors are functioning correctly.

also where do you keep getting this fictional running poorly idea from? who ever said my car's run poorly? not me that for sure.

The only issues I am having is poor fuel economy compared to what I get when I do not use Ethanol.

While I THINK the cars sound better on E0 that is purely subjective and I was very clear about that. there is no concrete difference that I can detect in operation EXCEPT for fuel economy.

NOT ONE of my cars is running poorly.

Anything else?

tjts is correct regarding obd I and II the only real difference directly related to the OBD was the encoding of the information. Previous to ODBII the manufacturers were starting to intentionally obfuscate access to the data to prevent easy mechanic/customer DIY repair.

Laws were past to force them to open and standardize to OBDII this did not change the actual cars or their systems.\

10-20-2010, 10:24 PM	#324 (permalink)
Nerys Grrr :-) Join Date: May 2008 Location: Levittown PA Posts: 800 Cherokee - '88 Jeep Cherokee 90 day: 19.44 mpg (US) Ryo-Ohki - '94 Geo Metro Xfi 90 day: 50.15 mpg (US) Vger 2 - '00 Plymouth Grand Voyager SE Ninja - '89 Geo Tracker 90 day: 30.27 mpg (US) Thanks: 12 Thanked 31 Times in 25 Posts	tjts - I would have to say your diagnoses is incorrect. the O2 sensor is fine. In fact it was one of the first things I replaced. I installed a new O2 sensor and when nothing changed in 2000 miles I removed it and reinstalled the old sensor Still no change. Are you seriously trying to tell me I have 10 bad O2 sensors and no codes ? the probability of that approaches zero. in fact while getting 17-18mpg in the jeep it suddenly started getting 9-10mpg about 2 years ago. It was the O2 sensor. I replaced it mileage returned to 17-18mpg but never to its correct 22mpg unless I got E0 I had a similar problem in the VAN but in this case the "wire" leading to the O2 sensor came out of its stay and came into contact with the exhaust which promptly melted it. Fuel economy off course tanks and it threw a code. I replaced the sensor and secured the pigtail better (the old twist lock thing that held it had become brittle) Mileage returned to its E10 lower ratings ie 13mpg. thats is 3 of my vehicles where I replaced the O2 sensor post ethanol. 2 needed it 1 did not. the 2 that needed it did NOT need it on ethanol. it failed POST ethanol for an unknown reason on the jeep and because of the melted plug on the van. I DO now have a scope now. once I learn how to use it I will even be able to VERIFY that the O2 sensors are fine. The minivan is OBDII and was checked both O2 sensors are functioning correctly. also where do you keep getting this fictional running poorly idea from? who ever said my car's run poorly? not me that for sure. The only issues I am having is poor fuel economy compared to what I get when I do not use Ethanol. While I THINK the cars sound better on E0 that is purely subjective and I was very clear about that. there is no concrete difference that I can detect in operation EXCEPT for fuel economy. NOT ONE of my cars is running poorly. Anything else? tjts is correct regarding obd I and II the only real difference directly related to the OBD was the encoding of the information. Previous to ODBII the manufacturers were starting to intentionally obfuscate access to the data to prevent easy mechanic/customer DIY repair. Laws were past to force them to open and standardize to OBDII this did not change the actual cars or their systems.\ Last edited by Nerys; 10-20-2010 at 10:33 PM..