2010 Forester turbo. Check engine light comes on. No cruise control.

Question

Replaced spark plugs.
Replaced spark coil.
Replaced Injector.
Replaced secondary intake valve.
Replaced timing belt.
Replaced gasket.

Only acts up when the engine starts from cold.  Once the engine is warm and reset the codes, it does not code until the engine is off and cold again.  Warmer weather seems to help from tripping the code on initial start-up.  Upon a cold start the engine runs slightly rough. After the engine has run for a few minutes it smooths out and if the codes are reset it runs normally.

Answer 1

When the engine is cold it needs more fuel. Once it warms up the fuel trim goes lean. When the code is cleared it reset the long term fuel trim. Check the fuel pressure regulator. when at the fuel pressure regulator see if the vacuum hose is secure and not broken and the fuel pressure regulator if you pull the vacuum hose there is no fuel seepeage out of the regulators vacuum hose connection