When I put my car over 10 pounds of boost and I step all the way down on the gas it starts like jumping and shakes what can I do to fix these I bought my audi a4 a few days ago and need help the guy that sold it to me told me it had a apc chip no idea what is these need some info can someone help me ....

 

Sounds like a misfire.. Does the check engine light come on? Did it do this when you test drove it before you bought it? and by "apc" do you mean APR?

 

yes is apr andit does not do it when its under 10

 

and the check engine light does turn on

 

Take your car to autozone and have them scan your ecu for fault codes. They will do it for free. Write down the codes and post them here and we will help.

 

sounds like miss fire

 

Check the codes - probably a misfire...

 

Post the codes here. Probably a coil pack but can't tell without the codes.