I bought a 2001 camry with the 5sFe engine as well. V4 . Its been quite reliable. It has a overheating issue sitting, unless i turn the air on. I just gave up on fixing it . Other than that , nothing out of the ordinary for a 20 year old car. I had a cracked thermostat housing, replaced timing belt and water pump . The valve cover gaskets tend to leak on these, not a super expensive fix . Here a video on the most common issues on that gen of solara. video 1aauto actually to have very specific and useful information regarding lots of makes and models. I would definitely get a mechanic to take a look. I only spent 2300 on mine. Had it 3 years, my dumb ass rear ended some 1 month in. Still running tho
Have you tried new gas?