looking for live data base readings to diagnose CEL

Hi all

I have a 2001 1.6 petrol Elantra in Edinburgh Uk, the Check Engine Light came on after I stalled and jerked the car restarting very hard, at first i thought it must be mechanical like failed clutch due to hard take off, but maybe electrical surge? strange.. up to that point no engine problems, an old car at 2001 but only 35,000 miles on clock and ran extremely smoothly. After a while of running engine light on I got rough idle and changed plugs, then took to garage that scanned O2 sensor or coil pack so i changed couil pack that fixed the rough idle of third cylinder not firing.

Still CEL light on so bought a scanner and changed upstream O2 sensor P0141 I think from memory, then also changed post CAT downstream O2 sensor and CEL still on, I cleaned the throttle body intake thoroughly, and when I delete the CEL with scanner the car runs super smooth, last week i gave the car a long run and with CEL on the revs stsrated to idle up and down from 500 to 2000 at times, then erased CEL and car smooth again. Car still reads P0141 and P0135 for 2nd O2 sensor, used cheap ebay sensors as replacements

Have the live data feature on my scanner an 'OBDMATE OM12' so thinking it may be worth taking the readings and comparing to what the baseline for the car should be then can post again, would appreciate if anyone could direct to me to what the live data figures should be for the car? or if such figures are available?

thanks

Rob