its been a month since i put on my mac o/r h-pipe and today my check engine light came on. at first i thought damn mil's failed but when i looked under the carthe zip ties i put on had gotten loose and the passenger rear O2 sensor got dragged across the ground and damaged. well i unhooked my battery for a couple of minutes and the check engine light has gone away but im wondering what will a damaged rear O2 sensor do to the performance of the car and will it have any effect of gas mileage?

-Archemy

 

bump

 

Im pretty sure the only function the rear 02 sensors have is to make sure ur cats are working properly, thats why people usually turn them off with a tuner

 

wait a minute, your o2 sensor fell out? anyway, the main purpose of the rear sensors is to monitor the efficiency of the cats and let you know if they're not working properly via the CEL. only the fronts control how the engine runs, believe it or not i've been driving around without mils for almost a year and my car runs fine

 

you said you have mils. just plug the o2 sensor back in and dont worry about it. the mils send a resistance so that it tricks the comp that they are working right. so even with bad o2 sensors you will be fine with mils. so dont worry bout it

 

my car tripped the cel because of an o/r x pipe and it runs like ****. I have to keep unhooking the battery to turn the light off until I can get my hands on a tuner. My mils didnt work. The car runs great until the cel comes on, then it idles really rough and stalls sometimes, until I unhook the battery and start all over again. The rear O2s on my car definately effect its performance.

 

first time i've ever heard that, are you sure that's the only code it's throwing?

 

well it definately was running fine when the light came on. i just wanted to make sure they wouldnt effect performance, the mils are working fine its the O2 sensor itself that is messed up. i can live with the CEL on until i can get a new O2 sensor.

 

the rear o2 sensors read but with the mils on them they throw a resistance in the line before it sends to the computer saying everything is working great. so dont even worry about it.

 

My friend's eclipse GT is running like sh*t as well... the rear o2 sensors have failed out about a year ago... and she has been driving around without them... some mechanic tried to get her to believe her car is going to blow up eventually (BULL) but it really is running bad.... it guzzles gas worse than my 4.6, and when we were in a parking lot, after starting it up the rpm's started fluctuating between "almost stall" and 1000... but once she got back out onto the street it was running fine... so I think that there can be prolonged problems...