havent had my seven long so not sure if its meant to do this, was going down the motorway and as i put my foot down and went through the gears the exhaust kept popping a lot, and when it popped the car felt like it was stuttering, like power was going on off on off, what causes this??

 

try plugs and wires

 

its due to get a service soon so i'll get new spark plugs fitted then, hope that sorts it

 

New plugs and/or fuel filter.

 

if i have a full system exhaust could it be the fuel is running lean and its to do with the detonation??? its coming from the rear of the car though not the engine, but that was a suggestion from another board.

its the apexi n1 exhaust if any1 has one have they experienced this???

 

yes, you are running too rich and the excess fuel not burned up in the combustion process is getting pushed out the exhaust. Happens more on cars with catalytic converters but mine pops a little too.

 

assuming i change the plugs and the prob doesnt go away what do you guys suggest? a power fc?

 

Take one step at a time. Do as everyone suggested above (normal maintanence):

1. Change oil/filter
2. Change fuel filter
3. Flush coolant
4. Change spark plugs and wires
5. Change O2 sensor

That will give you a good basis to start with. After that, if you are still having problems you can diagnose them from there.