I have a '92 ranger 4x4 with a 2.9 and a 5 speed. Recently I noticed about a month ago It started to idle a little rough and now when I rev up to 3,000 rpm's or more there is a bad vibration. I know its not in the driveline. I pulled codes and got 41 and 67. It also recently had a tune up about 3 months ago.. What can I look for? Thanks

 

KOEO 67 is almost always operator error. Computer expects to see the test performed with the transmission in neutral -- this code is set if the transmission is in gear when test is performed. Since you didn't specify if this is a KOEO or CM code, I'm assuming it's a KOEO code.

CM 41 points to a fault in the O2 sensor data. Do you also get a corresponding KOER 41 (being sure to preheat the engine/O2 sensor immediately before the test)?

You say you've eliminated the driveline as a possibility, I'm going to assume this has been adequately eliminated. How about other elements of the drivetrain (transmission mounts, rear end, tires, etc.)? If the engine is misfiring, that can cause vibrations and cause a 41 code. On the other hand, bad data from the O2 sensor could cause the computer to overcompensate and cause a misfire.

If this were me I would proceed as follows:
1) Repeat KOEO test with transmission in N to be sure KOEO 67 clears up.
2) Perform KOER test (properly preheated engine) to see if I get a KOER 41 (or other KOER code). Be sure to follow instructions carefully, as there are a couple of KOER codes that are commonly operator error.
Where we go from there depends on the results of the KOER test.