Check Engine Codes / P0171
P0171 Code
System Too Lean (Bank 1)
What it means
The engine is getting more air (or less fuel) than expected — unmetered air is sneaking in or fuel delivery is weak.
Can you keep driving?
Yes, short term. Long-term lean running can overheat the cat and cause misfires.
Common causes
Listed most-common first. Fix cost depends on which one it turns out to be — check your quote free below.
⚠️ Don't get ripped off
A cheap can of MAF sensor cleaner fixes a surprising number of these. Be skeptical of a fuel pump quote before anyone has smoke-tested for vacuum leaks or cleaned the MAF sensor first.
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Related codes
Informational only — codes share symptoms across vehicles, so proper diagnosis on your specific car always comes first.