Need some help after our actions did not fix the problem:
Outback got an oil change and check before a trip in September, at 135K miles. For the first time I experienced the car not shifting into lower gear when accelerating up a hill on the highway. The RPMs went up, but no downshift. I slowed down and the problem did not return.
Two weeks later the car died at idle in drive on an incline and threw code p0028. Car started idling rough at a stop or when in reverse at very low speed. Sometimes it died but restarted fine. We found some moisture in the spark plugs and tried removing. Ended up breaking a wire so we took it to our trusted mechanic for new plugs and wires.
After that the car performed well for two weeks until last week on a trip in the foothills. Threw the p0028 code while on a straightaway, but the idle problem did not return like before.
We cleared the code and chose to install a new variable valve timing control solenoid. We also cleaned the switch. The code is gone but the car is again idling rough and sometimes dying at idle in drive or reverse. Today we put in a new switch. Husband confirmed switch and solenoid are opening properly. But no change to our rough idle. We drove it around the block, it did not throw a code.
What is our next best option?