Do you lose power if the O2 sensors are bad?
 

I know that you lose a great amount of power if the KS is bad but my O2 sensors are bad...Am I losing power or no?

Thanks,
Sam

i would like to know that also...I heard, but i am not sure, that the 2 on the ypipe relate to performance, but the last one is only for emmissions. Anyone else have better input on this??

Yes you do. Your car will try to compensate and run richer/leaner. Replace them as soon as you can.

How do you know if they're bad?

There are 3 02 sensors on the Max. The one behind the catalytic converter has NOTHING to do with the vehicle power.

The other two are used by the computer to regulate fuel/air mixture, so potentially can cause lost of power.

Sam

Will a bad O2 sensor trip a check engine light or is it a ghost code like the knock sensor?

Any/all bad O2 sensors will trip the check engine light.

Sam

my O2 sensor near my rear header popped out from my warpspeed y-pipe yesterday. i think when i installed it i didn't tightened it all the way. anyway i lost some gas mileage and my shifting was not smooth at all.

anyway after i tighten it, everything is back to normal. so therefore yes.

I've been wondering the same thing myself. Every now and then I pull a 0702 CEL but I just reset the ECU and it's fine for a while. Changed the spark plugs this past weekend and noticed that the plugs showed signs of the engine running lean. Also when driving normally or semi-aggressive the engine seems to have a hesitation to it. No loss in RPMs or stutter but not a smooth feeling as I accelerate. I ran some BG44K fuel injector cleaner through it before I changed the plugs and haven't noticed any difference in the way it accelerates.

the one i had behind the cat was bad and i didnt change it for like 5 months. i didnt experience any loos of power. just had the cel light on. im not sure about the other o2 sensors

how do you know that knock sensor is gone bad?

o2 sensors will only affect performance when you are at partial throttle. When you are at partial throttle the ECU is in closed-loop. The ECU relies on the o2 sensors to adjust A/F ratio in closed-loop. When you are at WOT o2 sensors WILL NOT affect performance because the ECU goes into open-loop. The ECU relies on a programmed setting for air/fuel and timing(MAP) when it is in open-loop and the A/F will not change.

So would this truely be a bad or failing o2 sensor or a downside to WOT performance mods when you're not at WOT? Or is it better to re-map the mixture with an AFC or reprogrammed ECU?

Ask Neal. He runs 13's all motor on street tires with bad 02 sensors.

Yeah but Neal could run a 13 in reverse or on 3 wheels.