Cat temps?

[Millennium Falcon]

Driving up the hill the other day on a moderate, 3 mile-long grade, A/C on, 105* air temps, and no trailer, my converters hit ~1800*. What temps are considered too high in the converters? Thanks.

 

[Doubeleive]

Driving up the hill the other day on a moderate, 3 mile-long grade, A/C on, 105* air temps, and no trailer, my converters hit ~1800*. What temps are considered too high in the converters? Thanks.

that's "maybe" a little on the high side according to some, mine will hit that driving on the highway but I drive like madmaxx

 

[Dantheman1540]

How are you guys measuring the temp? Just curious I don't have a NNBS but do they have a gauge or readout for cat temp?

 

[Millennium Falcon]

How are you guys measuring the temp? Just curious I don't have a NNBS but do they have a gauge or readout for cat temp?

I use this: https://www.amazon.com/Veepeak-Blue...id=1597337747&sprefix=veepeak+,aps,267&sr=8-6 with Carscanner app on my android phone. As far as I can tell, it's accurate. I believe it just reads the info as the sensors report it. It shows more info than I can do anything with.

 

[Dantheman1540]

I use this: https://www.amazon.com/Veepeak-Bluetooth-Diagnostic-Supports-Vehicles/dp/B076XVQMVS/ref=sr_1_6?crid=2G2A642XKZWV3&dchild=1&keywords=veepeak+obd2&qid=1597337747&sprefix=veepeak+,aps,267&sr=8-6 with Carscanner app on my android phone. As far as I can tell, it's accurate. I believe it just reads the info as the sensors report it. It shows more info than I can do anything with.

That's cool that the NNBS have an option for reading temps off the factory computer.

 

[swathdiver]

How are you guys measuring the temp? Just curious I don't have a NNBS but do they have a gauge or readout for cat temp?

It's a calculated temperature which I gather that the data comes from the downstream O2 sensors. Keith, that doesn't seem not normal given what you were doing. Mine hit 1500+ just mildly accelerating onto the highway.

 

[Dantheman1540]

I used to drive a 2012 2500 express van conversion thing for work and it only did a maximum of 15mph 24 hours a day and 7 days a week only being turned off for holidays and maintenance. It was a 6.0 flex fuel truck and we had a contract for E85 really cheap so that's all it ever drank. Well, every month or so the engine light would come on for clogged cats and the maintenance dudes would tell us to jump on the highway and run it for about an hour at 5,000rpm. It would clean the cats out and then when they cleared the code it would stay away for a month or so.

That poor truck hated being held that high for that long but it did it and never let us down.

 

[Millennium Falcon]

It's a calculated temperature which I gather that the data comes from the downstream O2 sensors. Keith, that doesn't seem not normal given what you were doing. Mine hit 1500+ just mildly accelerating onto the highway.

Thanks, James. I agree that the temp readings must be coming from the O2 sensors since there are no other taps into or around the cats.

Dan, I still have my '02 Suburban with about the same mileage as the Yukon. If I have time this evening, I'll plug the reader into it and see if there are any readings for cat temps. Even if it doesn't, yours could have the temp readings since there were some significant changes in the '03 model year.

 

[Millennium Falcon]

Dan, I plugged the reader into my Sub today. GM didn't monitor cat temps in the '02 Subs, but 2003-06 could be a different story.

 

[RockGlock86]

If I could piggyback a question. Has anyone seen uneven car temps? One cat 150-200 hotter than the other?

 

[thompsoj22]

I used to drive a 2012 2500 express van conversion thing for work and it only did a maximum of 15mph 24 hours a day and 7 days a week only being turned off for holidays and maintenance. It was a 6.0 flex fuel truck and we had a contract for E85 really cheap so that's all it ever drank. Well, every month or so the engine light would come on for clogged cats and the maintenance dudes would tell us to jump on the highway and run it for about an hour at 5,000rpm. It would clean the cats out and then when they cleared the code it would stay away for a month or so.

That poor truck hated being held that high for that long but it did it and never let us down.

Sounds like the " maintenance dudes" were hoping for an engine replacement! LOL, Just wondering what the camshaft rpm is at 5,000 crankshaft rpm? Or wrose yet the roller on the cam follower/lifter? Nothing wrong with rpm but sustained 5k for an hour is an endurance test!

 

[Dantheman1540]

Sounds like the " maintenance dudes" were hoping for an engine replacement! LOL, Just wondering what the camshaft rpm is at 5,000 crankshaft rpm? Or wrose yet the roller on the cam follower/lifter? Nothing wrong with rpm but sustained 5k for an hour is an endurance test!

Even worse, despite the number of hours the engines stayed on the mileage was always very low so they only did oil changes once a year.