Engine problems

Hello guys i would very much like ur help on somthing thats come up on my clio 197. my engine management light has come on and the computer says emissions problem. i went to a kwik fit nearby and they plugged it in to the computer and 2 codes came up,

1) P0300= random/ multiple cylinder misfire detected.
2) 02 Sensor heated circuit[ bank 1 sensor 2] = po141

Just wondering what these are and if any of u could give me some information before i go into a garage and come out poor lol. wold really appreciate some advice Thanks a lot

Sion
 
Looks like the post cat o2 sensor it coding. Is the car decatted? If not there its likely the sensor at fault. The other code could be an old code from running outta fuel or somethin although mayb not.
 
if it was me - clear the codes and drive the car and then check again when and if the ecu light comes on...

the p0300 - you will be lucky to actually find what causes it - its basically a code that comes up when the ecu cannot pinpoint the fault!