what happens if O2 sensor is broken

[Dreamspeed]

hey whats up, anyone tell me exactly what happens i when your 02 sensor is broken? i drive a civic. does it only make your car run richer or does it do something else too? does it affect performance or only emissions

[91TSiAWD_Mark]

It usually makes you run as ritch as possible.
You'll get horrible milage. I used to have a 86 Jetta. It got 30MPG the O2 sensor went. I got 10MPG till it got fixed.
It won't do too much else though. It might retart timing, but Im not sure on Hondas. But its mostly an emmissions thing.

[Mystik]

on my dsm my o2 sensor is bad and i run rich as hell becuase of it. gas mielage suffers.. basically what mark said :)

[Dreamspeed]

well that's what i thought, but i also heard that if you run too rich too long it can kill your cat, not like i really care about emissions but...

[Dv5GreddyCivic]

DreamSpeed...you need to get it fixed...you wont be able too SMOG your car if thats broken...runnin too much fuel....

[Chris]

yeah it can destroy the cat. Youll also smoke like shit and on OBD-II usually your timing is retarded.

[invisibleman850t]

and you will carbon deposits on the back of your car

[Dreamspeed]

thanks for the info, i've recently got the o2 sensor replaced with a NGK/NTK unit but the engine light is still on and when i check the error code it is the same one but my dad checked the fuel and emissions and he says that the sensor is working now...

[SE-Rage]

What is the check engine light for? If it is for the EGR valve, then that could be the problem, because a faulty EGR valve or valve failure can result in detonation.