Originally Posted by PharmCo
What is really weird is that I have normal EGTs. About 1300F at cruise. Once I go on boost I can't really sustain 1400F EGT because the car really starts to buck after about 5 seconds over 8psi. I really hate to start replacing parts without knowing what is wrong but I guess I'll buy another front 02.
I wouldn't start replacing parts either - you have another problem that I don't think is related to your front o2 sensor being bad. Are you SURE the only CEL you're getting is P0171? If you're getting bucking above 8psi it sounds like you're hitting a fuel cut for some reason. Could be a tuning issue, could be a loose hose, could be something entirely unrelated to all the stuff in this thread.
My advice: don't buy the o2 and don't start throwing parts at. Start a new thread in the appropriate forum - make sure to list ALL of your mods (relevant or otherwise) any recent work done on the car up until the point where things started to go wrong, all the symptons you can think of and all the steps you've taken thus far to try to remedy it. Shoot me a PM with the link and I'll help you bump it up and throw my 2c in it- I may not be of much help, but others on here know volumes more than I do about general troubleshooting.