Bad oxygen sensor and Bosch wideband extenders?

[NSXonwheels]

I bought 2 new uego wideband oxygen sensors because I'm getting some off readings on my AFR gauge. However the harness is about 2 feet too long. Is there an extension I can buy or a proper way to extend the harness? Thanks in advance for the help.

And while I'm at it. When driving, the AFR readings are fine, but sometimes it will just go super lean, the engine noise changes and it stays full lean for some time, then randomly it will pop back to normal readings and the car will run fine again. Is this the symptom of a bad oxygen sensor? I'm scared to push the car in case that super lean condition happens when I'm on full boost.

 

[Tech7042]

You can use a multimeter to measure the voltage of the o2 sensor in closed loop to see its rise time. The voltage should jump low then high and low then high and have a good response rate. If it doesn't, it means the o2 is lazy. To do this, back probe the input wire to the o2 sensor and connect the red test lead to the probe, and connect the black test lead to body ground. Set the meter to volts and observe the voltage reading at idle and if you can, snap the throttle wide open and release it. This test will eliminate the o2 sensors as being the cause of incorrect readings.

 

[NSXonwheels]

Tech7042, I really appreciate your response, but I don't have a multimeter and what you said is beyond my backyard mechanic abilities. But I did do the brake cleaner in a rag test on both sensors and it went to full rich some of the times, I had to get the rag pretty soaked and move the sensor around in it to get it to read rich, and sometimes it didn't work at all so I would have to spray more cleaner and try again. I hope that helps. Anything else I can do to test them?

Also, I realized after googling the part number on the sensor that I ordered the wrong one. What I need is a Holley 510-554-101 LSU4 Bosch and I had bought a Bosch universal uego instead. Anybody know how long the LSU4 harness is? I need about 30 inches