Faulty O2 Sensor?
 

Have my turbo kit installed minus injectors, computer and a tune. Not building any boost. HOwever when i start my car up the air/fuel ratio reads 14.4 in a cold start, it used to sit at 13.6. When under full throttle it used to be at 12.8-13.2 now it is at 14.1. Can anyone guide me in the right direction, could it be the sensor for the air/fuel gauge or the O2 sensor?

^^^^^^heres your problem. ^^^^^^^^^^

without a tune you may want to stop driving it otherwise you will need to add a engine rebuild into your budget.

Even if im not building any boost? Everything is put together but the wastegate is open.

you hooked up your boost source to the wastegate incorrectly. the boost reference line goes to the bottom nipple on the wastegate, not the top nipple. the top nipple is a vent. if you run your boost/vacuum line to the top nipple then the wastegate will stay open.

Ok i wasn't clear enough. I am purposely not building boost right now because i do not have a tune, injectors etc. installed. So right now my turbo set-up is like real big cold air intake.

My issue is that until a few days ago my car cold started at an AFR of 13.6 now it cold starts at an AFR 14.4, and under full throttle my car used to sit at an AFR of 12.8-13.0 now it sits at 14.1. Could this change in AFR be due to a faulty O2 sensor or is it something else?

My bad on the confusion

theres no way to tell if the sensor is faulty unless you look at it with a scantool. i highly doubt the sensor is faulty. even though the turbo is not building boost it is still moving air into the engine. this maybe the cause of the full throttle lean out. what did you do to purposely not build boost?

turbo has an internal wastegate so i'm just holding the flapper open right now.

do u have an intercooler and a blow off valve?

What wide band kit do you have? What ecu do you have OBD1 or 2?

ya intercooler, BOV, the whole thing minus injectors and installed ecu. Just waiting on the ones i ordered to get here then get it tuned. I have an AEM UEGO wideband kit and just running the stock OBD2 ecu right now