Tsb 03-16-01 (p0171, P0174)

So I am getting ready to do this, while reading the TSB I noticed that Ford says to update your PCM. All of you that have done this fix yourself have you had any issues concerning the PCM not being reprogrammed, or have you gone to Ford for the update. Just curious if I should have it done or not waste the money.

i didn't update mine.

ditto

Mine not done either... runs much, much better than before the fix and cannot tell any difference in performance loss.

Great thanks guys, will be doing this work tomorrow along with the spark plugs will let you all know the results.

All done it went well other than I left the spring loose on the throttle control cables and it fell into the pit of despair. I did manage to find it laying on a cross member. Man those back plugs are bear to change, glad I put in the Bosch double platinum plugs. I sure hope this fixes the issue I have been having with getting these two codes repeatedly.

I do have one further question, is it possible a K&N air filter could cause the codes because its allowing too much air to flow to the engine intakes?

I doubt the air filters would let in too much air ... it would be too much dust that would concern me.

The common problem with the K&N and other filters that you oil is the fact that, if too much oil is applied, oil can get onto the air flow sensor (MAF Mass Air Flow) and cause the CEL to come on.
Of course, too little oil, more dust gets by and that is bad also.