Hey guys,

So last night I had my battery disconnected for over an hour while I was doing a steering wheel install and some other electrical work. I put the negative cable back on and just went inside. I remember on the way to work this morning that I should have let the car idle for 10 mins to let the ECU relearn all of the fuel trims and stuff.

Here comes the issue. I hit WOT in 3rd gear to get up to freeway speed and suddenly my CEL came one. I hooked it up to my code scanner and it said the code was P0143 which is no activity on the primary O2 sensor. Do you think that it is related to me not letting the car relearn it's stuff? It seemed to be idle weird all day too. I can monitor real time data on my scanner so I check it out and I saw plenty of activity on both sensors so I am hoping it was just freaking out a little bit.

Anyone else have any insight to this?

Thanks!

 

Slight update... I disconnected everything again and let it sit for awhile. Then I hooked it all up and let it idle for like 10 mins. So far no CEL, I might go drive the **** out of it to see if something comes up again. Hopefully I fixed my problem but I am still open to suggestions from peeps.

 

Hey guys,

So the problem is coming back. Maybe once a week the CEL comes on for a couple of hours and then it will shut off by itself. It is the same code: P0143 which is "No activity for 02 sensor bank 1 sensor 1". Anyone have ANY idea? My next move is to just replace the sensor but I would hate for it to be something more simple than that.

Thanks,
Square_1