Code P0171
System Too Lean Bank 1
Plain English Meaning:Your engine is getting too much air or not enough fuel
Yellow: Drive with Caution
Driving is usually safe short term but can cause long term damage
P0171 Symptoms
- •Check engine light rough idle hesitation poor acceleration
Most Common Causes of P0171
P0171 Repair Playbook
Required Mechanic Tests
A qualified shop should perform these tests before replacing any parts to ensure they aren't guessing:
Check fuel trims smoke test intake inspect MAF fuel pressure test
Typical Fix Paths & Estimated Costs
Fix air leaks clean MAF fuel pump or injector repair $100–$800
Parts for P0171 Repair
Common replacement parts for fuel system codes. (Paid links)
🚗 Get Vehicle-Specific Search
Select your car to update the links above for a guaranteed fit.
Paid links — we may earn a commission. Please verify fitment details on the retailer site.
Fair Pricing Guides
Check our database for average parts, labor, and expected repair costs before heading to a mechanic.
🏷️ Current Fuel System & Injectors Coupons
5 live offersReal, current fuel system & injectors coupons and discounts captured from national chains and repair brands. Updated automatically.
$50 Off Any Repair Over $500Min spend $500National · works anywhere
26th Street Auto Center (Los Angeles)
Last checked Oct 13, 2026$120 Off Vehicle Service (Spend $850 or More)Min spend $850National · works anywhere
Hyundai of Downtown Los Angeles
Last checked Oct 13, 202626th Street Auto Center (Santa Monica - Near 90210)
Last checked Oct 2, 2026Rebate — money back after purchase$50 Mail-In Rebate on GM & ACDelco PartsNational · works anywhere
GM Parts / ACDelco
Last checked Oct 2, 2026Up to $60 off Fuel System CleaningNational · works anywhere
Firestone Complete Auto Care
ServiceBuddy may earn a commission from some partner links, at no cost to you.