Just did a fresh engine swap. Car is running good except for my o2's, causing the Check Engine light to be on. (I need to do emissions!)

I connected the OBD2 Reader and it's not getting any type of signal from either o2's.

I've replaced both and nothing.

I'm replacing my alternator today which has gone bazurk... but I can't foresee this being related to the o2 malfunction.

Any ideas??

Thanks for any help

 

Update:

The car has been sitting for close to 5 years now, I'm unaware of whether or not this could of been an issue before hand but if I remember correctly I did not have any kind of codes prior to my engine blowing up.

Could it be a ground?

What's a good way to diagnose the source of the issue?

 

anyone?