1998 GMC Sierra codes P0172, P0175, P0404

[quote="dslman"]Engine problem
1998 GMC Sierra V8 Four Wheel Drive Automatic 91000 miles

I just bought this pickup and the service engine soon light has come on and these codes are the ones I pulled out. Can anyone direct me where to go from here? The light has gone off for about a day but recently came back. I have not checked what codes are there again, but will soon. Thank you.[/Quote

well, I made a donation when I posted this question and still no reply Feb. 29. I guess the donation is just a scam!