[harryhaller]

for the last 6 months i have been living with a failed o2 sensor. the check engine light went on and stayed on but i had no difficulty with the engine or ride and the gas milage was fine. however when the summer came and when you thought milage should improve it did not. for $290 plus labor i was lothed to have the sensor replaced. am i doing damage to the vehicle? i have 100,000 miles on it now and the fiqures dont add up re: cost benifit ration. any thoughts?

 

[sunhunter]

You can replace it yourself easily. It will still cost $200 for the sensor though. Buy it online.

 

[Joeatslo]

A $200 dollar part to keep problems from starting on the $2000 dollar part... seems like you'll save $1800 in the end by replacing the o2 sensor yourself - and its easy to DIY. You may want to check the cat - 6 months is a long time to have a bad o2 sensor especially if you do short drives. then again i put 20-40k miles on a car in any given year. and you can read all the post in here where they go into detail on the possible damage and ramifications about bad sensor. Just click search (above next to FAQ) and type in "O2 sensor", "P0134", "P1162"...

 

[Dr. Ali Fant]

Dear Insighters:

Beginning this fall, my two counties of "Travis" and "Williamson" in Central Texas will require air checks to pass inspection. I found out from the dealership that the "official" rules are that the Engine Check light MUST be off in order to pass inspection. The exhaust isn't even checked for quality, just a quick peek (and $$$) to see if the Engine Check light is on.

For those of you with older cars, you might find it difficult to bring the engine exhaust up to standards. Then again, if you go into an inspection with a lighted Engine Check light, a note is made on the official report which will require these modifications in order to register the vehicle.

I am not advocating anything illegal, but in Germany all the air check inspection required was a chemical wipe of the external three cm of the exhaut pipe. The solution for older cars was to cut off two inches and weld on a new two inch pipe segment. The inspectors would wait while the shop made this modification to the tail pipe.

Remember, Engine Check lights do burn out.

Sincerely,
Ali Fant

 

[joecvt]

Many places are now connecting to the ECM via OBD-II port to check
for check engine condition so even if the light bulb does "burn out" or
"get covered with majic marker" they will still be able to tell.

JoeCVT - Just your average CVT owner

 

[flunkysama]

The ECM has maps that control the amount of fuel to inject depending on throttle, RPM, temps, etc.etc. The O2 sensor is used to "trim" (i.e. make adjustments up or down) to the amount of fuel injected. So if everything is working just as it should, the lack of O2 sensor data should not be that big of a problem. But without the fine tuning the O2 sensor provides, you are wasting gas, making more pollution and maybe shorting the life of your engine. You are being penny-wise, pound-foolish.