I have 2009 camry that starts but will go in limp mode and
decrease to 20mph . When I pull off the road and shut it off
and restart it I drive normal for a while and does it again.
Need to know what codes are stored in computer. Many Auto Parts stores will read these codes for FREE. Write down the code numbers and descriptions and get back to us.
That's the cars equivalent of passing out. You wouldn't grab a human being and force them to keep walking after repeatedly passing out would you? Take the car to a shop and get the problem diagnosed. Limp mode is the engine computer's attempt to prevent damage to a motor due to a mechanical failure, most likely timing related.