My check engine light came on and it called for both O2 sensors on bank 1. I replaced the sensors and check engine light went off after I disconnected the battery for 20 minutes to reset the computer. After driving the beast around for about 20 miles the check engine light came back on. Went and had the code read and again it stated the front O2 sensor. I told them I just replaced it and they erased the code from the computer (again). Again after about 20 miles it came back on. I have checked the connectors and double checked them again. Has anyone had this problem? Any clue as to what I can do next?

I forgot to mention that it is a 5.4L 4X4 and the code is P0141.

Thanks for everyones help!

 

Can anyone please give me some feedback?

 

Looking forward to what the pros have to say...

 

Sounds like you don't have something plugged in all the way. I replaced mine about 2 yrs ago. It was a royal pain in the A$$ to get the plug undone and then to plug in the new one. It took longer to unplug the sensor and plug in the new one than it did to change the sensor. My check engine light came on once after I changed my sensors. It was 2 months later though. I erased the codes and never saw them again. This might be a stupid question but, have you checked your PCV elbow on the rear of the intake manifold? This is a common problem. The rubber elbow that goes onto the manifold gets old and brittle and developes a hole in it. This will cause all kinds of codes to come out and none of them have anything to do with the problem. The entire assembly must be purchased from the dealer at a cost of $35. It should take you about 15 min to replace. Just make sure the engine is cold..... it is really tight behind there and you will get aggrevated if if you get burned on a hot engine! You will have to do it mostly by feel because there is no way to see back there. It is helpful to remove the Throttle body cover on the top of the engine. It will give you a little more room. Hope this helps.

 

A PO141 is a "too lean bank 1" right? Just changing the O2 sensors won't fix a lean condition. I suggest checking for a vacuum leak.

 

My check engine light was on and I just had my car scanned I have a 95 Mercury Grand Marquis with a 4.6, it came up with two codes po141 and ho2s12 Heater circuit fault. Then went to the obd test and said Heater circuit bank 1 sensor #2. Can anyone please help me, I was told i would get about 21 to 25 mph and I'm only getting about half that.

 

^You need to replace your post cat O2 sensor on the passenger's side of the vehicle. I'm not sure exactly what you have but unless its a 4 cyclinder 21-25 MPG is unlikely.

 

Well it said in the scan it didn't say anything about the O2 that tested ok. No its not a 4 cyclinder 4.6 v8 and this came from a mechanic at a Ford dealership who is my uncle. Plus i have talked with friends that get almost 30 MPG on trips

 

i didn't mean to post....sorry, i cant find a way to delete, only edit