air/fuel Gauge

My issue is I have two gauges fitted in my 2014 Challenger 392 when I start up from cold and hot, my right hand bank gauge allways reads correct shows fuel ratio at all given revs.

the left hand bank gauge is a nightmare !!!. very regular it takes ages to show fuel ratio readings it shows the htr, when it does work, it goes mad sweeping from left to right cuts out then reboots itself cuts out again then shows 22.4 ratio for ages,code comes up E8  fitted new O2 LS 4.9 sensors for the second time it wired up as per instructions when the E8 code shows I disconnect the Live wire re connect and it works  just can`t work it out all wire connects are secure and earthed good any idea`s