spluttering/slow start++diff probs

[benjamino]

hey guys,,
the first few problems with my car are coming to my attention,,

firstly::if im at a standing start and accelerate (very)fairly i can hear the exhaust start to splutter a bit (seems to go almost nowhere) and the car has no real kick at all off the line at all..
what could this be??
ie,cats,backpressure etc..

and also,

if im cruising along at say 80, or even 100, and a slowly put my foot down, i can hear (and feel) a single *knock as i presume the gears changes down.sometimes i get fairly rough gear changes also.
ive already had the gearbox serviced and they say evrythings fine, could this be diff problems?

appreciate any help anyone can offer.
cheers

[wetwork65]

I have exact same problem. Yesterday closed the spark plug gaps from 1.3mm to 1.0 mm on advice from others.
Hopefully this will help out.
Interested for others' advice and experiences.

[VrWagz1]

How old are your spark plugs, sounds like you may have a bung plug.

[benjamino]

i had a major service when i got the car in april,
so theyre that old.
but they could b bunged stil i guess?
ill check them out tmro sometime.
cheers.

still interested to hear some other thoughts

[benjamino]

turns out it was the plug leads.
down to supersht to get new ones,
bosch high performance leads.

runs fine now.
so there u go.