Lean on idle and stoichiometric while driving

[turbo wagon]

Hello,
I have a Rob Tune and I was wondering if I could check the CEL.

I used the 93 NA wiring harness that was in the car for the swap, with all of the supporting mods.
The car was running great up until last week.

This issue I am trying to figure out is:

1. In the past the AFR ran rich between shifts, but the car idled and drove at 14.7 and around 12 at WOT
-----This was just fine and the car ran great. this was for about 2 years----

2. just this last week the AFR at idle was in the 15-16 range but when driving the car it would go back to 14.7.
----This was ok to get the car to my house from work for a few days---
---Now the AFR at idle is 17 and driving it stays at 16-17 range---
---The car is parked---



Ideas?????

[Alphius]

Vacuum leak or bad O2 sensor are my first gut feelings.

[turbo wagon]

Solved...

Yes, is was the O2 sensor. swapped out, ARF's safe and back on boost!

Thanks

[Alphius]

Awesome! Just another example of the diagnostic power and additional safety inherent in running a wideband.