Fuel System
Code P0171
System Too Lean Bank 1
Plain English Meaning:Your engine is getting too much air or not enough fuel
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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
1Vacuum leaks dirty MAF sensor low fuel pressure exhaust leak
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
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Parts for P0171 Repair
Common replacement parts for fuel system codes. (Paid links)
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