kstng50

My light was going off and on for a few weeks now and i got the code pulled P0133 Upstream Heated Oxygen Sensor circuit Slow Response - Bank No. 1. My question is I had to replace the gromet on the gas tank because it was leaking. Now after i replaced that a few days later the light went off do you think having that leak could have set the light off or should i be replacing the o2 sensor?

jdaniel

I would replace the upstream O2 sensor. The gas tank has nothing to do with that code.

kstng50

i wasnt sure because some people were saying when that code is pulled it isnt always the o2 sensor sometimes it is something else. i just thought it was weird that it went out after the gromet was replaced. I thought it might have something to do with having a leak in the fuel system setting it off.

ahollings52

your check engine light is capable of doing very little, if nothing more than tell you if your air/fuel ratio isn't right, via signal they recieve from the oxygen sensor, if i'm not mistaken

the upstream o2 sensor is actually capable of affecting your air/fuel ratio, by determing (through exhaust gas temperature) if the car is running too lean or too rich (to lean being hotter, too rich being cooler) it then sends a signal back to your ecu, which it takes into account along with the signal the MAF sensor and temp sensor (located right near your MAF sensor) to adjust your air/fuel ratio accourdingly. when the ecu can no longer compensate for a variation in one of the signals (usually due to a faulty part) it'll throw a code, and your check engine light'll pop on

the downstream o2 sensor is really only responsible for making sure your cats are working properly, and doesn't actually have any affect on the fuel delivery

in other words, sounds to me like your upstream o2 sensor's bad, and you should swap it cuz it might be robbing you of power (or leaning things out too much, which can be worse)

don't take what i saw for certain though, i could very well be wrong, wait for some other opinions too hehe

kstng50

i think ill just buy a new x pipe and change it all at once