It doesn't happen at slow speeds just in 4th and 5th gear and when I take my foot off the accelerator it still continues and even goes faster.
The car is in motion and the engine suddenly goes faster. on 2006 Saab 9-5
Sounds like the throttle body is not backing off and getting stuck in position. Need to clean the throttle body and see if this alleviates the issue.
Many thanks for your advice, I will try it.
1 more answer
possible sticking throttle cable.