How to Diagnose P0171 and P0174 Lean Codes Faster
Diagnosing a P0171/P0174 system too lean condition doesn't have to be complicated. This Tech Tip Short breaks down how to use OBD2 scan tool fuel trim PIDs — including long-term fuel trim diagnostics and mass airflow sensor data — to pinpoint the root cause fast. Whether you're dealing with a vacuum leak or a fueling strategy issue, monitoring how fuel trim data responds to throttle changes tells you exactly where to look next. A smoke machine test makes finding leaks simple. Watch the full tech tip short now and add this efficient lean condition diagnosis method to your toolkit. For more information, visit www.autozonepro.com.
About the Author
Erik Screeden
Technical and Multimedia Content Director
Erik Screeden is the Technical and Multimedia Content Director for the Vehicle Service & Repair Group. Erik is an ASE Master Automobile Technician with L1, and L4 credentials, who has been in the industry for over 25 years in various capacities. During that time, Screeden was a technician. He started out at a Ford dealership and continued to several independent repair facilities as well as spent time in the specialty aftermarket at a GM-specific performance shop. After his time as a technician came to an end, Screeden transitioned into a role providing scan diagnostic and J2534 tool support. He was then able to parlay his experience as a technician and a support specialist and use that in several technical sales roles.
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