2008 5.7 Tundra catalyst temp reading

Error codes all over the place. Im reading catalyst temps with OBD and they seem to be right on the money. Upstream at idle 718°......Downstream at idle 334° .
I keep getting a dtc of catalyst system malfunction. I also have airbag dash light on but no code stored.

Anyone else have this issue

 

Welcome. I’m pretty sure those cat temps are calculated values, not real temperature sensor readings. They’re kind of bologna.

 

Thanks, although the readings on my OBD are in F° or C° it would seem to be actual temp readings. And from research, these numbers are close to accurate.
My question was, has anyone had the catalyst code pop up on there OBD? Sorry, I cannot remember the code number.

 

There are no temperature sensors in the exhaust to read those values, only o2 sensors. They aren’t real measured temperatures, they’re estimates by the ECU. If you’re going to compare readings before and after the cats, I’d look at the o2 sensor readings not temperatures. Many people have had cat related diagnostic codes. If you would like help figuring out the issue you will want to provide the codes you are getting. Is it both banks or just one? It could be failing cat(s) or o2 sensor(s).

 

Thanks appreciate that. If the code comes back I'll take note. From what I remember, bank1 sensor 1 and 2 were the same. As well as bank 2 sensor 1 and 2 read the same. Bank 1...pre cat read higher than bank 2, which seems correct.

Have you had luck with catalyst flushing?