Low top speed. Can't do e-check. O2sensor problem.
I have a 92 E150 inline 6. Today I took it to have an e-check but when they put it on the dyno they couldn't get it up to 60mph in order to conduct the test. It seems to run fine but I do have trouble going above 60 most of the time, though when I moved recently and had the van heavily loaded down I could get to 80mph.
Just before I moved a mechanic checked out why my engine light was coming on and said that it was giving code number 179 and that it was an O2sensor problem. This code says "Adaptive fuel lean limit reached at part throttle, system rich, at right side".
So my questions are;
1. Is it likely that my O2 sensor is bad or should I check something else before replacing it? (keep in mind the 92's don't have an MAF)
2. Just load it down with junk and take it to get checked again hoping it will run like I did when I moved.
thanks in advance for any info you could give me.