CEL Codes, what's wrong
 

Trying to get a work truck back & running, it's a 99 F-250 with a 5.4.. These are the codes it's giving 1131, 1254, 171, 174.. Doesn't have much power on the freeway, if you get into the gas or RPM's to far it just doesn't react & bogs down. I know these are lean codes, is it most likely a problem with cloged ports & such??

P1254 appears to be an invalid code. Please recheck.

P0171 & P0174 together are usually a vacuum leak, usually the PCV hose elbow. SEARCH keyword "P0171 P0174".

P1131 is a weak upstream O2 sensor on driver's side. Since yuo also have the codes related to vacuum leaks, fix those first as a vacuum leak can skew the accuracy of the O2 sensor tests.

Steve

Sorry, 1254 is really 1151

P1151 (driver's side) is the complementary code to P1131 (Passenger side - please correct previous notation).

Follow my advice given above as is still applies.

Steve

Thanks for your help, I'll check it out once it warms up a little more around here...