Can I just install new oxygen sensor bank2, sensor2 by splicing wires to old connector? Seems getting to this connector is very troublesome and the likelihood the problem is the connector is very small.

 

Yes, you can. In fact, some non-OEM O2 sensors come with pick-tail (end connector). That O2 sensor wire goes through floor pan and up alongside the transmission hump and connects under the carpet on side of hump.

 

# 2 Oxygen sensors location.

 

I did that on my LS430.

The "pigtail" connections are the ones that have the plastic harness already wired into the sensor, so it's plug and play. You can get ones with just the "dangling" wires and splice them in to the existing wires. The universal ones that come like that are usually quite a bit cheaper.

The downstream O2 sensors (after the catalytic converters) are not really crucial sensors like the upstream ones are. It's basically just giving a pass/fail reading for the catalytic converter. In fact, i just used an old O2 sensor and spliced it in. I was doing some exhaust work and the original sensor had become seized in there and stripped the threads. I didn't want to shell out a $100 for a factory spec one, so I just spliced an old one in and it seems to be working. No check engine lights.

On an upstream sensor, I would heavily lean against splicing one in as any sort incorrect reading could cause issues.

Rarely though does replacing a downstream O2 sensor actually address the problem if you're getting a check engine light.

 

That's good info Bradtank