P0172 System Too Rich (Bank 1) | Black Smoke, MPG Loss & Injector Fix

Is your exhaust smelling like rotten eggs or raw gasoline? Is your car puffing black smoke? You likely have code P0172 (System Too Rich, Bank 1). This means your engine is burning too much fuel and not enough air—the exact opposite of a "Lean" code. In this video, we explain how to read Negative Fuel Trims on your scanner and why a leaking fuel injector or high fuel pressure is often the culprit. We’ll also cover why a dirty MAF sensor might be "over-reporting" airflow, tricking the computer into adding too much gas. Timecodes: 00:00 - Intro: What is P0172? 00:23 - Technical Definition (Negative Fuel Trims) 00:40 - Symptoms (Black Smoke, Gas Smell, Soot on Tailpipe) 00:57 - Top Causes (Leaking Injectors, High Fuel Pressure, Bad O2 Sensor) 01:45 - Diagnostic Steps & Solutions 02:36 - Summary Need the full diagnostic flowchart? Read our full guide to learn how to perform a "Fuel Pressure Leak Down Test" to find leaking injectors: ► Full Guide: https://obdadvisor.com/codes/code/p01... Recommended Tools for P0172: Fuel Pressure Gauge (Essential for testing the fuel regulator and pump) https://amzn.to/4apyfex OBD2 Scanner with Live Data (To monitor Short Term Fuel Trims) MAF Sensor Cleaner (To clean a dirty sensor element) About OBDAdvisor: We provide professional-grade automotive diagnostics and repair guides to ensure you get the right fix the first time. Disclaimer: This video is for educational purposes only. Always consult your vehicle’s repair manual and take appropriate safety precautions. A "Rich" condition can overheat and destroy your catalytic converter very quickly—address this code immediately. #P0172 #SystemRich #FuelInjector #BlackSmoke #OBDAdvisor #BadGasMileage