Need o2 sensor help with code P0141

Hey guys,
Trying to figure out what's going on with my car. I have to get this solved by like Thursday in order to get my inspection done and avoid paying for a no inspection ticket. My SES has been on, and Autozone told me it's code P0141, which is the o2 sensor (bank 1, sensor 2).
We replaced that sensor, and the SES is still on. Tried clearing it by unhooking the battery, then driving more than 150 miles now since putting it all back together. So I'm wondering if anyone has ideas why it would still be throwing the code, and what I should do. I'ts a 2001 V6. Any help is appreciated.

Bank one is the front of the motor as you face the car....sensor two is the downstream sensor past the precat. If that's the one you replaced and you're still throwing a code, look at bank 1 sensor 1. It's likely throwing too low a reading for sensor 2 to measure the differential.

That is the one I replaced. I can check out sensor 1 tonight. Is there a way to really tell if the sensor is bad besides throwing a new one on there?

You could measure the voltage output, but that's somewhat difficult and requires a pretty accurate volt meter. Try cleaning the bank 1 sensor 1 sensor and reset the code. Only problem with any of this is when you reset the code, the inspection station is going to notice when they run the diagnostic test and tell you to come back in 1,000 miles. At least that's what they do here.

The guy at the inspection place said he would pass me if it wasn't throwing a code when I took it to him again, so we'll see how it goes. I'll clean and check 1 tonight and see where I'm at. Thanks.

I just had my code set about 2 weeks ago too, and I changed both at the same time, to save trouble trying to figure out what's going on. I was told that when you change one, the other one being older might not be able to keep up measuring the levels from the newer one in the front if you changed the front one, thus causing the code to come back on.

You might as well change both, since they are not too hard to change and I bought both from Rockauto for the cost of buying one from Mitsubishi.

I ordered the other one just now from advanced auto parts. They'll have it here tomorrow. Hopefully that solves the problem. I'll have them read the code for me when I pick it up to see of it's still throwing the same thing as before.

Now the mechanic is telling me that I've been replacing the wrong sensor. He says bank 1 is the head towards the firewall bc that is cylinder 1. How come everything I've read here seemed to suggest the opposite?

Found this on Stratus Forums:

NOTE: Sensor 1 indicates the sensor mounted at a position closest to the engine, and sensor 2 indicates the sensor mounted at the position second closest to the engine. NOTE: Bank 1 indicates the right bank side cylinder, and bank 2 indicates the left bank side cylinder.

Same Note in the Service Manual. Damn the mechanic is right and I was wrong...I'm terribly sorry...the front of the motor is on the passenger side of the car so bank one is the rear.

It's all good. I've read several threads that suggested that bank 1 was toward the front of the car. It's confusing when every part and every person says it a little different, and with the engine turned sideways.
Everything is good now, and I've just passed my inspection. Luckily the sensor I had purchased originally was the correct one, and so I was able to put the old one on the wrongly replaced one, and the new one on the bad one. All codes are cleared now, and good to go.
So for clarification for anyone in the future, bank 1 of the V6 Galant is toward the firewall/rear of the car. And you are correct about which sensor is which, 1st is pre-cat at the engine, 2nd is post-cat.
Thanks for the help.

Glad to hear it Heather. Again, my apologies for the mistake, but happy you're back on the road and codeless again

Need help on finding a o2 part# in either http://www.autozone.com or http://www.oreillyauto.com for Bank 1, sensor 2... I have a feeling the autozone guy is giving me the wrong part..

Autozone guy is giving me this

I'm thinking it should be this part

Quote:

---

Originally Posted by DrunKenG

Need help on finding a o2 part# in either http://www.autozone.com or http://www.oreillyauto.com for Bank 1, sensor 2... I have a feeling the autozone guy is giving me the wrong part..

Autozone guy is giving me this

I'm thinking it should be this part

---

Well i ended up getting this one since it's Bank 1, Sensor 2. Now i'm having a hard time getting it off... any tips?

Try spraying it with PB Blaster, or any penetrating oil. It's probably seized up.
Make sure to use a line socket or box end wrench so you don't strip it.

I think that's the right part # from checking rockauto.

No more engine light :) ... To loosen the sensor, i started the engine to heat up the sensor then sprayed some freeze off......While it's still warm, i then used a breaker bar with an O2 bit socket.. i thought I stripped the sensor at first, but it ended up just coming loose.... The part i picked from autozone was the right part...

Cool, glad to hear you got it taken care of.