What does this mean P0141 & P0420

[DannyDynamite]

I have had my check engine light on for bout two weeks. I finally borrowed my friends tool to read the lights and this is what I got.

P0420 Catalyst System Efficiency Below Threshold (Bank 1)

P0141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)

How do I go bout fixing these things? Anyone who can help thanks in advance.

Anthony

 

[Eneurb]

Normally a heater malfunction code means that the oxygen sensor it self is atfault, but you can't rule out a wiring problem. If there is a problem with the sensor, it likely caused the catalyst efficiency code.

 

[monkeydude3]

Ok I checked my chilton book and here is what I found

P0141~ HO2S circuit shorted to ground, open or shorted VPWR circuit

P0420~ Catalyst efficiency monitor and/or exhaust fault


I'm not sure if that helps much, I can't find much else in this book

 

[Skibug]

If your after cat O2 sensor fails it probably will trip the 420 code in the process. If the after cat sensor gives a faulty reading, the computer senses that the cat is not doing it's job and will give the 420 code. Mine did the same thing. Only mine did not spit the two codes out at the same time. I ended up replaceing all of my O2 sensors and it cured the problem. O2 sensors give out over time because of the carbon build up in them. And usually if one is bad, the others are soon to follow. When I got the same exact codes as you, I just replaced the after cat O2 sensor and it fixed those codes for a while. And then about 3 months later, another O2 sensor threw a code and I went ahead and replaced the other two.

 

[DannyDynamite]

Do I have to go to a mechanics to replace the O2 sensor..or is that something I can do myself?

 

[Skibug]

Do you have the V8 or V6? I changed all of mine with no problem at all. Get you a Haynes repair manual and get to it.

 

[Eneurb]

Do I have to go to a mechanics to replace the O2 sensor..or is that something I can do myself?

I guess that all depends on how mechanically inclined you are... there probably aren't that many O2 sensors out there that are easier to change than a downstream.

 

[TPLYNCH]

Before you change it, make sure the wires to/from the sensor haven't been damaged causing a short. I believe there is also a fuse/relay, that if blown will give the 141 code.

 

[jimbo74]

Before you change it, make sure the wires to/from the sensor haven't been damaged causing a short. I believe there is also a fuse/relay, that if blown will give the 141 code.

where is the fuse/relay for this? my moms 96 v6 spit out a 0141 code

 

[jimbo74]

ok, since i have posted in like 5 threads now... i think i have located the at fualt sensor... however the threads i am seeing are for a v8.... there is only 1 o2 sensor behing the cat.... there is a Y pipe that connects the left and right side manifolds to each otehr than goe into the cat, coming out of the cat is 1 o2 sensor... is this my p0141 - bank 1 sensor 2? i looked at the wires and they dont appear to be frayed or shorted or toching anything either