Need help with P1151 code!

[mcdavidhome00]

Hello everyone. I am puzzled by this problem I am having with the oxygen sensor code P1151 in my 4.0. I'm experiencing a slight miss when idling only when I come to a complete stop after when driving.

Could these 2 problems be related, meaning can the O2 sensor cause your engine to idle poorly. So far, in my efforts to correct the problem I have replaced the ignition coil, wires, and plugs with Bosh double platinum, and cleaned the throttle body.

Oh and I guess I need to mention probably an important detail. My truck wasn't driven for at least 6 months due to my transmission failing. But during that 6 month period I cranked my truck 3 days a week and let it run for 20 minutes each time.

Any thoughts, comments, or suggestions would be greatly appreciated.

 

[410Fortune]

What is the code?
Since the transmission was just replaced I would check the wiring connector to your oxygen sensor bank 2 sensor 1
It is quite possible it did not get plugged back in fully or a pin got bent
Depending on the code, if it is a heater circuit failure or sensor not switching code then it may simply be time for a new 02 sensor they do wear out. They are heated and heater elements do fail quite often
You should post the actual trouble code

 

[mcdavidhome00]

What is the code?
Since the transmission was just replaced I would check the wiring connector to your oxygen sensor bank 2 sensor 1
It is quite possible it did not get plugged back in fully or a pin got bent
Depending on the code, if it is a heater circuit failure or sensor not switching code then it may simply be time for a new 02 sensor they do wear out. They are heated and heater elements do fail quite often
You should post the actual trouble code

My apologies the code is P1151 Lack of HO2S21. I will certainly check the wiring and is this the pre cat o2 sensor?

 

[Stynx]

My apologies the code is P1151 Lack of HO2S21. I will certainly check the wiring and is this the pre cat o2 sensor?

Upstream is pre cat downstream post cat. Given that you had a lot of work down there it's a fair guess that it's the sensor wiring. I'd get under there and double check connections all over.

 

[mcdavidhome00]

Hello everyone. I am puzzled by this problem I am having with the oxygen sensor code P1151 in my 4.0. I'm experiencing a slight miss when idling only when I come to a complete stop after when driving.

Could these 2 problems be related, meaning can the O2 sensor cause your engine to idle poorly. So far, in my efforts to correct the problem I have replaced the ignition coil, wires, and plugs with Bosh double platinum, and cleaned the throttle body.

Oh and I guess I need to mention probably an important detail. My truck wasn't driven for at least 6 months due to my transmission failing. But during that 6 month period I cranked my truck 3 days a week and let it run for 20 minutes each time.

Any thoughts, comments, or suggestions would be greatly appreciated.

***UPDATE*** After replacing the Bank 2 precat o2 sensor the code finally went away and the rough idling stopped. The wiring was fine but after observing the live data of the o2 sensor voltage reading, I noticed the constant back and forth switch was slow. My research stated that this process should be very fast so I'm thinking this was the cause of the problem.

Thanks for all of your help in diagnosing this issue. I also learned in the process how many o2 sensors I had in total and which bank was the passenger side and driver side. This info helped tremendously in my troubleshooting. I would not have been successful without you guys expert help!

Oh and one more thing and I guess this is probably just common sense, but would it be a good idea to go ahead and replace the other precat 02 sensor anyway even though its working fine? It seems logical enough to do that since its neighbor has already failed. What do you guys think?

 

[Stynx]

I just went through this with my mechanic. I had bought 4 new sensors using the same reasoning as you, even though mine were still working fine. Got under the truck to get the first one off, hosed it down with penetrating oil and went to work with the special O2 sensor socket and a breaker bar.

Broke the socket as it was so frozen. It dawned on me that there might be a problem bigger than me.

I took it to my mechanic and he patiently explained how on a 20 year old vehicle, things like that were likely to be hopelessly galled and if you tried brute force you risked wrecking the equally old exhaust system and you were much better off leaving it alone until it actually failed and that it might never fail so why tempt fate?