Shaking in overdrive

[matthewst]

My 1992 XLT shakes when it's in overdrive on level pavement and going uphill. Downhill is not a problem and it doesn't matter what speed I'm going. I pulled the trouble codes and got a "181 (M) Fuel system was lean at part throttle Single, Right or Rear HO2S". I don't know what that means nor how to fix it. I already cleaned the MAF sensor thinking if it couldn't sense the correct amount of incoming air then it wouldn't know how much fuel it needed. No luck.

Anyone else have any experience with something like this?

 

[MrQ]

That code says your passengers side O2 sensor is not working properly.

 

[matthewst]

Well....now it's just obvious.
Thanks!

 

[huntman58]

Your 92 uses one O2 sensor and the code you got is for the O2 sensor. Before changing it you started out right by cleaning the MAF so now also look for any vacuum leaks, an air leak in the air tube after the MAF things like that.

When was the last time the O2 sensor changed? Most consider it a part of a tune up any more and replace them at about 60,000 miles. They can run longer but as they get dirty they degrade also.

Do a fuel pressure check and also check you FPR vacuum line to see if there is any fuel in it and that it is hooked up right. Fuel filter could also do this with starving the motor of fuel under power were going down hill its needs are less.

Just some things off the top of my head to check or look to