I got my car smogged today and it failed and nothing is done to it, its completely stock. But when i was looking at why it failed the NOX emissions were about 100 over what they are supposed to be. My CO measurement was 0% from the sniffer in the tailpipe and my oxygen was at 4.35. Which tells me that the car is running extremely lean. I left it at the shop for them to diag it and they found a Super chip in the computer. What I am wondering is can they just pull out the chip and leave it like that or is there something that goes in its place. They are waiting for an answer from me, any help will be very appreciated.