Subaru Problems? Ask a Mechanic for Answers ASAP
Which engine is in yours - the 2.5 or 3.0L
Hi there. Different expert here.
Data Trouble Codes (DTC) don't necessarily indicate a component is bad. In this particular case, the onboard computer has set P0170 because it is having difficulties setting fuel trim. Most of the times, replacing the Oxygen sensors doesn't cure this issue; instead, the fix is achieved by cleaning the mass air flow sensor (MAF) - just be sure to use the appropriate cleaner (click here for example).
Also, you might want to check that the air filter housing and hose to the throttle body are properly seated and not allowing unmetered air into the engine.