O2 at idle - Where should it be?

[Antbankstwo3]

When I start my car, O2 is at 400 then slowly drops between 40 - 80 & stays there. When I start driving it does fluctuate (which I heard it's supposed too). When I'm stopped at a light or in traffic, it'll drop as low as 30 - 50 & stays.

I've replaced all vacuum lines & checked for leaks. I have a new exhaust (no cat). I installed a Denso O2 sensor. LT1 MAF & Translator are new. Setting is at "3", the WOT is at "0". All other mods are in my signature.

Exhaust smells a lil' off recently (rich), but I'm not too sure. Jus different than before. Any suggestions would be helpful. Thanks in advance!

 

[we4Mateo]

Probably a bad O2 since it started right after you changed it. Scanmaster readings at idle?

 

[Antbankstwo3]

I changed it a couple months ago. Should be still under warranty. I will get the readings & post them.

 

[TT/Ameasap]

Should be around 800mv

 

[Antbankstwo3]

Probably a bad O2 since it started right after you changed it. Scanmaster readings at idle?

Here are the scanmaster readings I just got after driving it home. Place it in park. There are the numbers at idle:

O2 835
AF 4
L8 28
Bat 13.7
Int 128
BL 124
Clt 179
Ats 139
r 875
TPS .46
IAC 21

I don't know why the 02's remained higher this time. IAC seems lower and I just adjusted it 2 weeks ago.

 

[we4Mateo]

Here are the scanmaster readings I just got after driving it home. Place it in park. There are the numbers at idle:

O2 835
AF 4
L8 28
Bat 13.7
Int 128
BL 124
Clt 179
Ats 139
r 875
TPS .46
IAC 21

I don't know why the 02's remained higher this time. IAC seems lower and I just adjusted it 2 weeks ago.

Everything looks good. Perhaps the O2 sensor wasn't getting fully heated before? IAC will change based upon relative humidity and barometric pressure changes so don't worry too much about that either. I think you are good until you are not good again and then post those numbers.