iponnet

ok my engine does burn gas and I think its the piston rings but once in a
while I hear this DING sound and a plume of smoke comes out of the tail
pipe and the engine starts to have idling problems as if it wants to
stall
and sometimes it does. and this has been happening more often lately, was
wondering what could cause this? are the piston rings getting so bad that
the oil is getting way upthere where the spark plugs are and shutting
them
off? or is the the knocking/pre ignition everybody talks about(scanned
the
computer no codes regarding pre ignition) now I know I have pretty bad
catalytic converters (still passed smog 3months ago) and a bad evap
system
but I really dont think these problems could be the cause of this. and
btw
how hard is it exactly to change piston rings on these cars..is it
possible to do this without taking the engine out of the car. any help
appreciated. thanks