GM P0171 P0174

Question

Cadillac 2001 4.8 liter engine. Code P0171 and P0174

Answer 1

P0171 Fuel trim lean Bank 1

P0174 Fuel trim lean Bank 2

Lean condition are usually cause by vacuum leaks, and a MAF (mass airflow) sensor not properly reporting. check and listen for any vacuum leaks that can cause false air , low fuel pressure can also cause this condition, and so can sparkplugs being worn which does result in lean misfire.