I've noticed recently that especially when I either first start up the engine or am stopped with the engine going (i.e. a stoplight, etc) that it feels like the engine is kicking and makes the entire car kinda jump. I was wondering if anyone had any idea what may be causing this or what I should do.

 

what year car is it?

 

Its a 2003 GS with about 80,000 miles on it.

 

there is a reprogram for the ecu for warm ambient cold starts. basically what you're probably experiencing is a misfire when the car is cold( when on start ups).

 

Does that only happen when engine is cold?

 

I have had a similar problem. When you start it up or are stopped with the engine running the car jumps or kinda jerks, right? It could be one of these:
1. You need to check and possibly change your spark plugs,they may be worn out. Or
2. You need to check the electrical system,something could be causing the spark plugs to to misfire.
Hope this helps you!