Catylitic Temp

[Prokopchuk_9]

i think my cats are on the way out..anyone know what temperature they are supposed too be??

[Nytemare]

Hot as hell

As high as 900*C(1650*F) is safe limits.

[minibike132]

Very very very hot. I don't think temp testing is very accurate, I have shot some that I know are good and had them way hotter then I thought they should be and shot some that were definately bad and had them the same temp as the other one that was good.

 

The thought behind temp testing is that a clogged converter will heat up faster, the best way to find this out is do a back pressure test.

[Prokopchuk_9]

Hot as hell

As high as 900*C(1650*F) is safe limits.

 

 

i just went for a ride got everything hot, pulled it inside and creeped underneath with a heat gun. i got 200*C before and 300*C after. the cats were at about 250

[jbt56]

Average operating temp of a converter is 1200-1500 degrees F. Really, all a cat does is superheat the exhaust, and burn off hydrocarbons.

[redvett]

If a cat goes bad on OBD2 you will get an SES light .

DTC P0420 Catalyst System Low Efficiency Bank 1

DTC P0430 Catalyst System Low Efficiency Bank 2

[ken1mod]

Gentlemen,

 

To the best of my knowledge, hot cats are working. Cool cats are not. I would wait for a code before replacing.

 

Ken

[redvett]

Just a reminder you have an 8 yr 80K warranty on the cats.

[minibike132]

If a cat goes bad on OBD2 you will get an SES light .

DTC P0420 Catalyst System Low Efficiency Bank 1

DTC P0430 Catalyst System Low Efficiency Bank 2

 

 

Those codes will set if the catalyst just stops working, if the converter gets plugged they will not set. The post catalyst sensors are looking for pretty even voltages as they would see with a working converter. They would also see even voltages if the converter is clogged up and not set a code.

[minibike132]

Gentlemen,

 

To the best of my knowledge, hot cats are working. Cool cats are not. I would wait for a code before replacing.

 

Ken

 

Hot cats are working, cold cats are not and super hot ones are restricted.

[Nytemare]

Yeah...for the most part...if they're clogged its your manifolds you want to check the temp on.

If you have a plugged exhaust, your manifolds and down pipes will be cherry red after about 15min on the highway.

 

The more CO you have in your emissions...the hotter the cats will get, there is a chemical reaction going on in there...the catalyst is any thing that is used to make the chemical reaction happen better or faster or both. It does not get used up...but does get covered up, or plugged.

 

When they start to go bad, you will smell a rotten egg like smell from your exhaust.

[Prokopchuk_9]

well thanks for the help. i know what happens when they go bad. they just sound weird when i cold start it. ill just run it till they are pooched i have a feeling one is. when i data log with efi it runs really rich at certain RPM too. its never done it before. i think its a cat on its way out.

[Nytemare]

Or an O2 sensor on the way out. That sounds more likely as a cat doesn't have anything to do with fuel trim.

 

Check the activity of your O2 sensors next time you are doing a datalog.

[minibike132]

Or an O2 sensor on the way out. That sounds more likely as a cat doesn't have anything to do with fuel trim.

 

Check the activity of your O2 sensors next time you are doing a datalog.

 

When a converter gets clogged the pre cat o2s will read rich at higher rpm's because the exhaust isn't getting out. If you watch map data it should when graphed almost mirror tps. If I think I have plugged cats I graph the 3 (tps, map and 02) and they are pretty easy to pick out if you know what you are looking for. I still do a back pressure test to back up the diagnosis but it's pretty reliable.

[Nytemare]

Or an O2 sensor on the way out. That sounds more likely as a cat doesn't have anything to do with fuel trim.

 

Check the activity of your O2 sensors next time you are doing a datalog.

 

When a converter gets clogged the pre cat o2s will read rich at higher rpm's because the exhaust isn't getting out. If you watch map data it should when graphed almost mirror tps. If I think I have plugged cats I graph the 3 (tps, map and 02) and they are pretty easy to pick out if you know what you are looking for. I still do a back pressure test to back up the diagnosis but it's pretty reliable.

 

Good to know.