So how about giving us some background on the car.
How many miles?
Any problems in the recent past??
Any work done on it besides changing plugs and coils in the recent past?
Any Modifications to it?
Are you running a stock air filter??
Automatic or standard transmission?
Has the Check engine light ever come on or flashed?
With performance issues you want to stick to basic diagnostic rules.
The primary rule is:
Simplest things first...... Then work you way up the diagnostic tree step by step from the simplest to the more complex.
With that in mind you could start with re-calibrating your E-gas pedal.
Also a simple "Vacuum test" with a PROPER VACUUM GAUGE.
Not a smoke test.
Those two things are very simple to do.
A proper vacuum gauge is very inexpensive and a valuable diagnostic tool.
The first Vacuum test to do is:
Find a place to connect the gauge directly into the intake.
Have the car fully warmed up:
Let the car just Idle (I believe you Brits call it tick over)
Record the reading and very importantly the action of the needle if any.
Ideal reading is 18-22 in.hg with a rock steady needle.
Watch the gauge for several minutes at idle look for any changes in reading or needle action.
Let us know how you go.