O2 sensor

Are replacing O2 sensors as easy as 2 bolts and a plug? Will the check engine light automatically reset by itself or do you have to get a code/programmer? Also are the upstream and downstream sensors or bank 1 and bank 2 the same part or different?
2003 2.7L 4wd. Thanks for any info!

 

yes, it's 2 nuts (12mm) and a plug. You don't need any special equipment to reset codes - just disconnect the negative battery terminal for a few seconds then reconnect it.

 

question 1. yes and no. the nuts are pretty well rusted on by now. if you try and remove them and strip something, youre in a heap of shit. make sure to douse the rust with penetrating oil. or if you have a die grinder and a wire wheel to go on it, you can pretty well clean the threads with it. just make sure to still use a little penetrating oil on the top of the nut where the wheel cant clean.

question 2 . yes, but you can clear the codes yourself. though if you do this youll have to run through all your monitors again. and your MPG may drop a bit during this process.

question 3. no. bank 1 is always the side that cylinder 1 is on, passenger. bank 2 is the opposite, where cylinder 2 is, driver. bank 1 sensor 1 or sensor 2 is what your looking for. only vehicles with true dual exhaust have 2 banks of sensors (4 total).

 

also, i just recently replace both of my cats on my 3.4L. I could NOT find where the o2 sensor connectors were. it looked like they went into the body somewhere, but didn't really make it a point to find out. it may be a tad bit difficult to disconnect them.

 

It's a 5min job if the nuts aren't rusted to the studs. If the nuts are seized to the studs.........30 minute job with a 25 min PB blaster soak.

 

Although that might not fix your problem.

Did you at least pull the code if so which one??

 

Yes, but you need to troubleshoot the DTC(CEL) before just assuming that you need a new sensor. Have you read the DTC(CEL) code?

 

Got the code from the dealership and found all the info online. Soaked the nuts with PB blaster. Ended up running back to the dealership to get new nuts, as the old ones were word and corners squared off. Was not a 5 minute fix for me due to my limited mechanical skills, but got it done. Now I have a new problem. Code PO441 but that's another story. Thanks for all the info. Sorry for the late thanks.

 

Awesome!!!!!

 

0441 seems like an electrical code. did you mess with anything between the tank and the fuel rail or the evap canister?

 

Glad the first issue was solved, now on to this one: Is your gas cap tight? I know it's a dumb question, but that's one of the ways to trigger the 441 code.

 

Gas cap is tight as far as I know. Havent checked to listen for the hissing noise when untightened, but I will. I did not mess w/ anything between the fuel tank and evap canister. After doing some research on here code P0441 could be a number of problems relating to the VSV evap purge system. Gas cap, VSV switch, stuck valve, etc.