any body cross this on their ranger? my check engine light came on on my 98 with a 4.0 automatic and 4x4. I got plugged in at O'rielly and it said it's running lean and bank 1 and 2. both oxygen sensors code. I can't believe both o2 sensors went bad at the same time. anybody have some help for me. thanks

 

it's usually not common to have both sensors go out at the same time but then again it's not unheard of. sometimes you could have something else causing the engine to run lean. I think you need to go to ford dealer and have them run a complete check on it. if it turns out that it only needs to have the O2 sensors replaced then do that or have it done.

 

In addition if I may,,,,,,,,,,,,,,,,
I would suspect the codes it threw were possibly P0171 & P0174 which are lean codes for both banks. If that is incorrect just disregard the rest of this post , OK.
What we might consider looking for is what would cause BOTH banks to read lean.
It could be two O2 sensors sticking lean, but as grindman said it not very common.
A MAF sensor that is miscalibrating could do this, and so could a vacuum leak from the intake manifold gaskets which by the way is quite common. The better thing to do is to watch the fuel trim at idle and at 2500 RPM. That would help confirm a vacuum leak, but something you can check right away would be the PCV hose and connection from the PCV valve and the hose that goes from there to the intake manifold. If that is the problem sometimes you can hear the vacuum leak too. Those hoses are known for deteriorating and splitting resulting in various size vacuum leaks.

 

Thank you guys for taking your time to help me.
I couldn't hear a vacuum leak but there still could of been one I couldn't hear so as it was running I sprayed wd-40 on vacuum hoses and connections hoping to hear a change. The was no change. I disconnected the battery to reset the computer then cleaned the MAF sensor (of which was dirty) and put a new EGR valve in. Well I had a commute to work and back and no check engine light. I don't know which solved the problem but for $50 bucks i'll take it. Thanks again

 

Crapper, one and a half weeks later my engine light came back on. So, assuming the last codes were the same reason for these codes I cleaned the surfaces of my gas cap and unhooked the battery to reset the computer. Well that worked for a week and a half and the service engine light came back. Geeze.
I ordered a new Ford gas cap and installed it and reset the computer. The following day, bam the light came back on.
I mean what the heck.
I used pin point propane to find a vacuum leak and couldn't find one. I can't believe both O2's would go at the same time.
Anymore idea's out there?

 

when was the fuel filter changed last? I've heard that even though it may not be clogged all the way even a partially clogged filter could cause that same code. question for you is the mileage increasing or the opposite? usually if both banks are running lean it increases the fuel mileage

 

What were and are the codes you are now getting?
Shooting from the hip and in the dark is not the best way to go here.
The codes don't tell you what part is defective, they do tell you which system is affected and many times will direct you to the problem area. There are a few hundred codes and trying to suggest a possible fix without knowing just which area can get expensive and cause a lot of grief. Can you help us out with the present codes it is now throwing?

 

finally I had some time to work on my ranger. anyway, I doubt the fuel filter has been changed but I know its something I know I need to do anyway. I do calculate my gas mileage often but, were I live in northern Illinois we have had terrible weather so I really cant say about my gas mileage rate.

 

the codes I got are po171 and po174 .

 

What happens here is, when the O2 sensors detect a lean condition most of the time a vacuum leak, they inform the computer of this and the computer increases the injector pulse width. If this gets worse the computer keeps trying to cover the lean condition by adding addl fuel until it reaches the end of its limits then it throws the lean code. Now we need to find the cause. Common problems were the PCV hose/fittings, intake plenum gaskets and sometimes a cracked plastic intake manifold.
Some PCV leaks had to be chased from one end to the other. Not all intake leaks can be found with propane or smoke machines. If you used the proper MAF cleaner it should last. There is a cleaner made especially for this purpose and anything else is asking for trouble. Suggest you redo the MAF sensor and thoroughly check the PCV system.