I replaced my clutch slave cylinder a d unplugged my downstream o2 sensor in the process after I got that all sorted and replugged it, it starts dying when it's warmed up. I hooked it up to my buddies Innova 5410 to read codes but it won't let me read them and just says the o2 and cat are bad and says emissions related dtcs. I looked at the live data and the first o2 sensor seems to be within range but the second stays at 1.275v until it's warmed up then dips to 1.008 a d the first dips to around .1 any ideas of what I should check first?

 

the engine coolant temp sensor that runs to ecu will eventually do a no start when warm as it fails.
it's cheap so replace. 8)