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Q: Codes P0171 and P0442 - is it a gas cap issue?

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Ran codes. Got code P0171 and P0442. I think the later could be a gas cap issue. The earlier appears to possible be several items, (Fuel Filter, MAS Mass Air Sensor, Idle Control Valve, ) I had CCVV and hoses replaced last Jan. 2016. at 100K. The light came on at around 107K.

My car has 109000 miles.
My car has an automatic transmission.

A: Hello. These "small leak" codes c...

Hello. These "small leak" codes can be very frustrating! Both of these codes (P0171 - lean condition, P0442 - small evaporation system leak) are the result of an air leak in the engine's air intake system. Causes can be leaks in the many rubber hoses in the air intake, leaking hoses from the secondary air pump, a fuel tank vent valve not sealing, a gas cap that isn't tight as you noted, and so on. I would recommend having your Check Engine Light inspected by a mobile, professional mechanic, such as one from YourMechanic, to diagnose the problem, get an accurate assessment of damage and cost estimate for repairs.

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