rmdl51

iTrader: (4)

Hello,

Recently I have noticed a gas smell on the car, my MPG sucks and it was until yesterday that CEL came on, car start running really rough, hesitates when accelerating and shakes at idle, RPM needle also drops randonmly.

I checked my code and I got 33, which is Oxygen sensor, I want to replace it and I was searching threads about it, most people say is easy but could you provide some input as to how easy or difficult is to replace it, if you have pictures of the location (of both sensor and harness connector) would be very helpful.

Thank you in advance for your help.

Levsimus

iTrader: (1)

Sounds like you're running rich as heck, which in consideration of the O2 sensor code, means you're definitely on the right track by replacing it.

If you can get the car up in the air, its super easy to find - its on the Y-pipe just below the firewall. You can't miss it. Its a 21mm hex, if I recall. Unplug it before unscrewing it - and may want to let it soak in some PB blaster or something similar, they like to get stuck in there.

You will need to use a crescent wrench/combination wrench to get it off unless you bought/borrowed an 02 sensor socket. I can't recall if its readily accessible with the Y-pipe attached, I always found it easier to do it with the exhaust off on most any car. Make sure when you go to install the new one that you leave it unplugged until its tight, or you'll twist the wires.

rmdl51

iTrader: (4)

Thank you very much for your input, I have replaced my Oxygen sensor but unfortunately the CEL remains on, I cleared up the ECU memory removing the negative ternimal of my battery. But the CEL came on again with same code 33.

I checked the harness and looks in good condition, I'm clueless, any ideas?

ac max 92

iTrader: (13)

Possible you got a bad sensor. They can be very tempermental. Even dropping it can render it useless. I'd maybe try taking it back to where you got it and exchange it. I had that same problem once and exchanged it and wound up being fine after that. If it's running rough aswell you may want to check if you have a misfire they can be notorious for failing injectors. I know for certain there is an 02 sensor right before the cat but i can't remember if there is another one by the front manifold. Even though the CEL came back on is it still running rough? Aswell did you clear the code from the ECU or just by disconnecting the battery?

rmdl51

iTrader: (4)

Today before changing the sensor the CEL went off and the car ran great, no hesitation, acceleration was excellent, but then after I replaced the sensor, I took it out for a spin and it was running good, but only for 2 munutes, CEL came on again and start running rough with the horrible acceleration, at idle RPM needle drops like it want to stall and intermittently vibration while driving at 45-50 MPH.

I don't know how to clear up the ECU codes other than diconnecting the battery. Isn't that enough to clear up the codes?

Levsimus

iTrader: (1)

As far as multiple 02 sensors, depends on whether its a Federal emissions or Cali emissions car. Commiefornia cars have two cats, but I believe still only have one sensor (I could be wrong here, I've never seen the Cali catted y-pipe in person but if I recall the diagram only indicates one 02 sensor on the mid-pipe just before the cat.) in the same spot - on the midpipe.

Mind you I have a VG30E, no idea what motor OP has, perhaps VEs are different.

rmdl51

iTrader: (4)

You are Correct, As far as I know and I have asked many people, there is only one O2 sensor, I live IN california and the car in question is a VG30E.

I probably try to get a replacement on the sensor, I have no other idea why I still have code 33.

Is it really bad to be driving it like this? I have drive to work and this is my only car, is almost 20 miles one way to work.

Levsimus

iTrader: (1)

Aside from potentially fouling your plugs and wasting gas (and it can foul the O2 sensor) no. If you really drove it long enough and hard enough (months) in theory it could ruin the cats but you'd have to be running REALLY rich for quite some time before you'd see any real issue there. Running a little rich won't kill the cats, running REALLY rich will ruin them over time due to overheating and subsequent melting of the substrate. If its just to and from work a day or two, nah, no big issue - if you're thinking of saying screw it and running the car for a couple months then yes, I'd be a little more concerned.

ac max 92

iTrader: (13)

[QUOTE=rmdl51;8901540]Today before changing the sensor the CEL went off and the car ran great, no hesitation, acceleration was excellent, but then after I replaced the sensor, I took it out for a spin and it was running good, but only for 2 munutes, CEL came on again and start running rough with the horrible acceleration, at idle RPM needle drops like it want to stall and intermittently vibration while driving at 45-50 MPH.

I don't know how to clear up the ECU codes other than diconnecting the battery. Isn't that enough to clear up the codes?[/QUOTE

Did you read the flash codes from the ecu? There should be a write up somewhere about turning the screw on the ecu to clear codes. Sounds like it was possibly just a bad sensor. I would exchange the sensor and still check to see if you have a misfire somewhere aswell.

rmdl51

iTrader: (4)

Ok, I have replaced the sensor again, and I still have CEL with code 33. I believe it can't be a bad sensor twice. My question now is why do I have a code 33 if the sensor is good? what could cause it?

I'm not an expert on this matter, so I have no idea how to check for misfire. would a misfire confuse the ECU to throw a code 33?

While I was below the car I checked the harness connector thinking it may be bad in that area but I can't find anything wrong with it. What else could it be?