Can you check OBD2 codes manually on a Toyota Solara?

Smart aleky answer: Yes. You manually plug in the OBD II code reader into the port under the dash and manually read the problem displayed on the screen. If, by "manually" you mean the pre OBD II days where you jumpered a connection and watched a light flash on the dash the answer is, unfortunately, no. Systems have become far too sophisticated and you'd be counting Morse Code type long and short flashes for hours trying to figure out what the computer is trying to tell you. The good news is, OBD II readers are loaned free by many auto supply stores. In many cases you can grab the reader, plug it in in the store parking lot, read the code and walk right back in to purchase the appropriate part (which is why they loan you the gizmo for free). Cheers