LS1 Bank 2 Lean problem

[N20LT4Bird]

My friend has as 01 SS, 6 speed, mostly stock, with cat back sys.
SES light is on. Bank 2 O2 lean. Watch the O2, and its hanging at about 50 Mv or so. Problem is, its intermittent. Other times, the o2 functions well. My first inclination is to swap the sensor and see. Could be lazy? What other possibilities are there if 1 bank is actually running lean?

[Joe 1320]

I would pull the harness to the 02 sensor and give both ends a good cleaning. I've seen many times the problem is simply an intermittant contact. The fact that other times it works fine is a prime indication the sensor is still good, it's the electrical contact.

[Injuneer]

Switch the left and right sensors. If the problem follows the sensor, its the sensor. If the problem stay on Bank 2 its the wiring or its actually running lean. What does the after-cat sensor mV look like on Bank 2? Does it "track" the low O2 millivolts of the pre-cat sensor? If it did, that would indicate a true lean problem.

[N20LT4Bird]

Good ideas guys. Thanks. His after cat sensors are simulated due to the loss of the CATs (why people still insist on doing that these days ) so ..........he will try switching sensors, checking wiring. Hopefully, it something simple like that.

[Injuneer]

If he doesn't have cats, all he has to do is put the after-cat sensor back in Bank 2 and see what it reads compared to the pre-cat sensor.... they should read the same....

[N20LT4Bird]

Your always thinking arent you? I'll see if hes got the old O2s.