Is it possible to have an incorrect code come up on a code reader?

What is your question?

My car was running really rough, and idling rough so we changed the spark plugs which seemed to quiet it down for a while, within the last couple of months my engine light came back on only twice, once saying misfire and cylinder 3, so we swapped out the spark plug and cylinder 3 and put it in cylinder four. And once for code p0335 code for a crankshaft position sensor circuit A. The only thing is I do not have any symptoms of a faulty crankshaft sensor. No stalling, or hard starts, the engine light does not come on all the time it hasn't come on in months since moving that spark plug Is it common for this code to come up and then never come back on and have no symptoms? Could something else be causing this code to come on? The only potential symptoms I have of a crankshaft sensor are occasionally jumpy RPMs or the car will I guess decelerate without me pressing the brake, mild engine vibration, but all of the big names symptoms for a crankshaft sensor I do not have.

What makes this problem better or worse?

There isn't really anything that makes it better or worse.e, it's just kind of random

How long has your 2006 Toyota RAV4 had this problem?

A few months.