p0171 and p0173?

Question

I checked fuel pressure-good, cleaned/replaced maf sensor and smoked tested intake for vavuum leaks-none found. 02 sensors readings normal. What else should I check?

Answer 1

P0171 Fuel trim lean Bank 1

On the brake master cylinder to the brake booster use a brake cleaner or carburetor cleaner that area tends to have vacuum leak and gets unnoticed, It would be better if you have your scan tool that would read the fuel trim data, both the long and short added together should be less than 10