Any thoughts from anyone about this. Got home started cranking out the spark plug replacement got it all done, closed the hood, fired it up with the new exhaust, and bam engine light is on. I do not have a code reader, but anyone have any thoughts on what this must likely is ?? Any help would be great. I disconnected the battery while working and made sure I hooked up all the wires, and even drove it around the block everything seems to be ok,

 

Did you gap the plugs? Also make sure everything got plugged back in.