Codes after 4-2-1 header install?
 

I'mI've got some ideas on how to solve this issue, but I want to get some other input in the meantime before the new O2 sensor is delivered. Last night I installed my new 4-2-1 headers. So for as I know, no damage occurred to the O2 sensor but I'm not leaving it out as an option. Everything went perfectly and no leaks in the exhaust however two codes popped up. P0171 and P0134. At first it was only the 134 code and the 171 code appeared today.
My thought is: now that it's testing only one cylinder, instead of all four at once the O2 sensor is confused and if I move it to one of the ports further down the line where it can test all the exhaust gas at once it should be resolved.
Of course it never hurts to get multiple opinions, thus my posting the question. All help is greatly appreciated.

where is the front sensor currently located?

It's pluged into the bung on the third pipe from the left. I cleaned it off with some carb cleaner yesterday just incase it got some carbon in it.