1999 Chevrolet Blazer

Engine Performance problem
1999 Chevy Blazer 6 cyl Four Wheel Drive Automatic

i have recently replaced my fuel even prior to doing tthat my vehicle has a loss of power at 45-50 mph I have scanned it and now have stored touble codes po452 and po404 how can I fix this or what is my next step
February 12, 2009.

Egr code po404 and po452 code evap cntrl system pressure sensor low. If I would have to guess, I would say you have a vacuum leak. Check around the egr, make sure it isn't sticking and as far as the evap code, they are really hard to find. You can have the system fogged to find the leak. And yes, a vacuum leak can cause a loss of power.

Let me know what you find.