Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
This applies to most vehicles Transmission limp mode locks in 2nd or 3rd gear (the transmission will not shift)it will slip pretty bad taking off from a start (engine rpms easily raising without a noticeable raise in speed) may slip badly the whole time depending on Transmission damage, typically able to achieve 45+ mph in trans limp mode .
Engine limp mode or reduced power mode usually has very limited throttle response and limited throttle angle so winding the vehicle out or getting above 25mph is much more difficult and is often accompanied by red electric bolt symbol on the dash and some vehicles display reduced power mode on instrument cluster
