(content copied from another thread for faster reply)
I am facing a problem in my city sx8 2001 model.
Bought this car 2 months ago and it had several suspension problems
1: While driving in mid speed (60-80 km/h) a car was floating on plain road
(Lower control arms had problem as rubber grip which is near of engine bay were almost flat. )
(steering rack was also messed up after fixing lower control arms, steering rack was very dirty and had an oil + water as mechaninc said and the shaft was cutted / out of balance and not able to repair so changed it.) (Problem was fixed but some nosies remaining and left side is little bit hard to turn)
2: While turning on left side specially on reverse there was some hard knocking voice like tuk tuk tuk
(Outer CV joint of passenger side was problematic and worn out so changed it.) but voice is still here and seems like the c.v joint was not a good quality or there might be C.V inner joint is problematic too in my opinion.Problem is somehow remaining
3: Car is vibrating specially people who sit on back seat feel it well and i also feel that while driving, car had cng and i removed it and it's height is also increased from rear end, i am thinking that there might be some spacers and due to that spacers my driving pleaseure is ruinned. car is jumping mostly vertically. Wheel Allignement guy said that the springs need to be replaced and due to cng cylinder they were comperessed and now after removing cng cylinder these springs are free so they are bouncing enough i have a feeling of loose grip from rear end.
4: Engine is changed by previous owner and it is D15b7 and now tried to tune on petrol setting, throttle body was bad (monster drinking fuel) almost 7 KM / Liter and now changed (bought a second hand T.B without sensor) and now it is better on fuel but car looses it's power certainly when switch on a/c idle is set on around 850 rpm and choke works fine too. Engine temp is also normal. valve / Tappets setting is now on fuel as per mechanic. (As per my observation the fuel avg is around 10-11 Km / Liter and it should be 13 
)
suggest a good economical guy or any solotuion specailly about C.V joints.
