O2 sensor problem - CEL P0140 - how do i fix?

[GeeZuzz]

The "Check engine soon" light suddenly turned on, and i bought a OBDII reader. The result of reading was 1 error. Then it displayed:

P0140
01/02

P0140 is the error code, i don't know what 01/02 means.

According to the OBDII manual, P0140 means:

P0140 Oxygen Sensor Circuit No Activity Detected (Bank 1 Sensor 2)

But i also found this on a page which had topic "1995-99 Eclipse Non-Turbo":

129	P0140	21	Downstream HO2S Stays At Center

Does anyone know exactly what this mean? The only thing i did to my car before the problem occured is changing bumpers and catback exhaust (to stock). Car is 1998 GS btw.

 

[Raph]

01/02 = Bank 1 Sensor 2 ist the Sensor after your catalytic converter..

a) your Sensor is bad
b)your cat is Bad ( unbolt your exhaust after the cat and look inside.. youll see if the cat is missing or not-the car will smell like a lawnmower)

Edit: is it a euro 4g63.. if so, to replace the second sensor, you have to get to the plug under the drivers seat.
- theres some universal ntk 4 wire sensors on ebay.de for under 50 euro.(wire it yourself)
-or at any parts store for under 90 euros (plug n play oem style.. bosch and NGK/NTK makes them)

 

[GeeZuzz]

Thanks for your reply. Its a 420A engine.

So this causes only "emissional damage" - and no harm to my engine at all? (so i should not be afraid of using the car before fixing)

Here is a picture from underneith my car:

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I don't know much about cars, but i assume the one marked with blue is the cathalytic converter. The only thing that happened here, is that there was a shield/cover hanging loose underneith it, and was removed. Could that cause any such problems? The rest (backwards) was an unoriginal exhaust system, and is now replaced with the original exhaust. including brand new stock muffler. I find it hard to believe that the cat is removed, as this job was done at some certified place, and it's of course not legal to remove it. But do you mean i would smell it if something is wrong with it?

I don't know what these sensor looks like, but i assume that the thing i marked with red leads to the sensor in question. Are we sure about that?

The "Check engine light" went on the first day i used the car after the exhaust was replaced, after driving approx 60 miles. So it seems pretty obvious that this problem is related to the job these people did when switching the exhaust system. Maybe it's not connected properly?

 

[schoffs4]

O2 sensors are fragile shock will dammage them if the cat wasnt replaced during exaust install i would assume the o2 was dammaged during install {done it before} hope that helps and both codes will be caused by the same thing most likley o2

 

[GeeZuzz]

Where exactly is this sensor located? And how can a sensor in a car be sensitive to shocks?

And can someone just confirm that it's completely safe for my car to be used - it's only unsafe for the environment?

 

[DGajre777]

Yes, the blue is the cat, the red is the o2 sensor. Unbolt it and replace it. The plug for it is under the driver seat.

Yes, it is only for emissions to ensure that the cat is working properly. People who run without a cat or a gutted out cat or a bad cat will have the light come on. You can disconnect your battery for about 5 minutes and connect it back. It may clear the Check Engine Light. If it doesn't, check your cat.

 

[Talesin]

The car is safe to drive with that O2 sensor faulty. If the sensor is dead, there could be no problem at all... just a code saying the sensor needs to be replaced, even if everything else (including the cat) is in proper working order.

 

[schoffs4]

yes the car is safe to drive , all the sensor 2 does is monitor the cat if the cat was bad or hollowed you would get a cat deficiency code it wouldnt stay centered. If an 02 sensor is dropped or shocked they will break

 

[TheRock0720]

I am awaking this dead thread... I am having this issue also on my Eclipse. I've replaced the O2 sensor and wire and am still getting this code.