weird codes after suspension work

[blkqx4]

And here i am thinking no more work need then cel came on. Got codes
P 0159 02 sensor circuit low response (bank 2),
p 0158 02 senser circuit high voltage ( bank 2)
Here is the weird one
C1901 chassis

Im not sure what that is. I got a blu tooth obd reader on my phone and does are the codes i got. Any one knows if i should be really worry about this. Or what they are.

[Towncivilian]

A 99 QX4 should not have any chassis codes, that's odd. At least, as far as I know, the SECU (smart entrance control unit, similar to BCM - body control module) isn't able to throw any codes that a generic reader could read. P0158 and P0159 are for the driver's side rear O2 sensor. Those codes can be safely ignored indefinitely, unless you have emissions testing in your area. Clear the codes and see if any return.

[blkqx4]

Thank u i cleared them. May be they wont come back. If anything should i just change that o2 sensor?
I did swap out the battery for the first time since i got it and she kept flashing instrument lights and when i turn the key wouldnt start i got out lock it/ unlocked than it started so after that i had all the work done this was all on the same day. May be battery reset the system or something.

[Towncivilian]

Yep, if the P0158/P0159 codes come back (or just one of them) the O2 sensor is at fault. Maybe the starting issue was the key chip not making contact with the immobilizer or something, who knows. If that happens again see if the security LED is blinking - if so, that indicates a problem with the security system.

[blkqx4]

Ok thanks will see