(NECRO) Driving around with a bad O2 sensor... what bad stuff can happen to my car?

[psteng19]

...other than running rich leading to bad gas mileage.

It's a bad rear O2 sensor (in the cat).
Been like this for 3 months, never got around to fix it. Probably won't until early next year.
Check engine light just came on couple of weeks ago. Was expecting it earlier.

BTW, car is '95 sentra 1.6 L auto.

TIA

 

[bunker]

I had a '91 Ranger 4 banger O² sensor go bad on my 640 mile trip home from college. Went from about 26 mpg to about 10 mpg. Most expensive damn trip I took in that truck!

 

[ScrapSilicon]

Originally posted by: bunker
I had a '91 Ranger 4 banger O² sensor go bad on my 640 mile trip home from college. Went from about 26 mpg to about 10 mpg. Most expensive damn trip I took in that truck!

there ya go..1st hand ...$$ gas mileage ..hiya bunker!

 

[psteng19]

Yeah, my mileage dropped down a bit too.
I used to get 350 miles to a tankful (about 35 mpg).
Now I'm getting anywhere from 250-300 miles a tank (25-30 mpg).

But I'm talking long term.
If I drive around like this for half a year or so, will I be burning any valves or other damage?

 

[StageLeft]

I bet the engine heats up quick in the winter

 

[PullMyFinger]

The worst thing that could happen is that it melts your catalytic converter. When your O2 sensor fails or goes out of range, your car will generally go into a failsafe mode, sometimes even into a total limp-home mode. This allows the engine to run rich so that there is no chance of causing detonation and burning a valve or piston due to a lean condition. The down side of this is that the extra fuel will have to be burned off in the cat which increases it's operating temperature and can drastically shorten it's life. Once a cat has been operated at temperatures beyond what it was designed for, part of the ceramic core will melt, cause a restriction, increase the internal temperature, cause more restriction, increase ..... you get the idea.

Should you replace the sensor now or wait for later? Well, a new sensor is generally around $50-$75 installed, a new cat could be anywhere from $200 - $500 installed. Your choice. Hope this helps.

 

[psteng19]

PullMyFinger, very insightful post.

My cat is already busted and I plan to replace it with a hi-flow performance cat - don't laugh - if I was going to replace it, might as well get some tiny performance out of it

 

[Bluefront]

"The worst thing that could happen is that it melts your catalytic converter". Well not exactly. The converter can get hot enough to melt other things....such as your carpet, and any wires in the general area. I think your airbag control unit is right there.

Not to mention you're polluting the air at a much greater rate.....much greater. Get it fixed.

 

[aws1975]

I bought a 88 Chevy celebrity 2.8 6 cylinder the oxygen sensor is bad I can't get it off and Midas couldn't get it off because it's a little stripped and it probably wasn't put on right this time does anybody have any suggestions on how I can get this fixed without buying a rear manifold my car runs OK then vroom vroom vroom happens anyone know any alternative to replacing a freaking manifold?