i have been having on going fuel problems but finally replaced the fuel pump and the truck feels great it responds better runs better its all around a better truck now. but do you guys think it would be wise to have it re-tuned. could my afr be thrown off a little by making this change

 

the pcm usually re-learns.

 

IMO if you were orginally tuned with low fuel pressure, more than likely your tuner compensated by richening up the values in your MAF or VE table. Now with good fuel pressure, you might be running rich? Was it a live tune or mail order?

 

i have a live tune so it would be a good idea to re-tune

 

or at least have the log it... has your MPG gone down or up any?