PO-172 check engine light

I got a check engine light on my 99 Honda Accord EX 4-cylinder, I got the code PO-172 bank 1 system too rich. Dealership told me it was the forward o2 sensor or fuel pressure regulator so I changed both and the light came back on then I replaced the rear o2 and the light still came back on. I have spent 400.00 already someone help me.