Catalytic Converter Temperatures - UltraGauge

My friend gave me his Ultra Gauge to program the trans temp for him. He is not into programming gadgets and asked for my help ... I have a Scan Gauge and figured out how to program his UG to read trans Pan/TC temperatures ...

Long story long, I programmed his UG and it reads same temp as my Scan Gauge ...
Problem solved! so what is my problem?

After I tested my UG code, I also created a page displaying the following:

Catalytic converter Temperature:
Bank 1 sensor 1 <-- ok
Bank 1 sensor 2 <-- ok
Bank 2 sensor 1 <-- same as b1s1
Bank 2 sensor 2 <-- same as b1s2

The problem is that b2s1 reads exact same as b1s1.
Also b2s2 reads exact same as b1s2.

I can see the temperature (for example b1s1 vs. b2s1) being close to each other but should not be exactly identical. I even drove on the freeway and city and the temperature were always identical. Not even 1 degree off!!! That doesn't sound right.

Sounds like the UG pre-programmed Cat temperatured are getting the same data.

My question is has anyone noticed this or solved this problem?

FYI, if it matters, I have a factory TRD Dual exhaust and my friend has a single exhaust but he never used the cat temperatures and I just used a spare UG page to display them. Once again I did not program the Cat converter temperatures and they were already pre-programmed by UG.

 

I'm no expert by any extent of anyone's imagination, but wouldn't the temperature come from the Oxygen sensors? Which are triggered to a pre-arranged temperature/ voltage based on fumes and necessary fuel burning, and air fuel ratios?? I would assume that the only time there would be a temperature difference would be if one is clogged or damaged and the other were fully functional.

 

Good question but my understanding is that bank 1 (cylinders 1,3,5,7) and bank 2 (cylinders 2,4,6,8) are on different sides of the v8 engine and the sensors are reading temperatures at different sides ... So I am assuming the temperatures should be close but not identical.

I see the temperatures going up and down very quickly and Changing continuously and they seem like a real-time readings and doesn't look like they are filtered.

The b1s1 and b1s2 are definitely always different so the reading looks correct for one side but the problem is that the other side tracks exact same temperatures. S1 is before cat and S2 is after cat.

 

Agree, but aren't both banks burning technically the same fuel? So the CAT would be reacting to the same chemistry on either side?? I would assume that you would start seeing differing temperatures if one bank stops to function normally, like a misfire or a clogged injector so the amount of gasses emitting would start being different so you would start getting drastically different readings... Again, these are just assumptions on my part based on what I've learned through the years... Hopefully someone who is actually a certified tech can correctly guide you on this question...

 

It sounds like if they are the same, that is a good sign as outlined by @blackdemon_tt. It is weird that they were not ever 1 degree off though. Maybe the UG code was wrong and was reading the same sensor? Wouldn’t be the first time a company had a bug in their software.

Do I need to install a catalytic converter cooler?

 

We definitely need a cooler or Heat exchanger for it. lol we are talking about 1000F or more ...

@blackdemon_tt has a good point but as you said no matter how perfect and balanced things are or how even the fuel burning is ... I was expecting some difference no matter how small.

 

Agreed, but like I stated, I'm no expert just an assumption on how it would work..... lol, Idk about CAT cooling, would kinda defeat the purpose on burning unspent fumes..

 

While we are on this subject, does a single exhaust Tundra have one Catalytic Converter?
Mine is a TRD Dual and it has 2 Cats as far as I know.

 

Technically 4, 2 on either side, the 2 rear ones can be removed from what I've heard and no CEL...

 

Didn't know that!
Are you saying all Tundras have 4 Catalytic Converters?
I looked under my car long ago and I recall only 2 for my TRD dual exhaust.
Maybe I should make another trip under there.

 

Cars with V6s or more usually have 2.. Tundras have 2 bulges on either side, assuming they're catalytic converters.. Not Toyota but magnaflow shows cats as 4, or 2 on either side..


https://www.magnaflow.com/collections/2008-toyota-tundra-catalytic-converters

Edit: Toyota parts catalog 2008+ its all the same up to 2020
https://parts.sparkstoyota.com/p/To...t-Pipe--Exhaust--NO2/63198383/174500S200.html

 

You weren’t mistaking mufflers for cats were you? TRD dual exhaust bolts up after the cats and doesn’t change anything with them.

 

No. I recall 2 Cats in mine before the mufflers but if I'm not mistaken , @blackdemon_tt was saying that there are 4 cats (post #9). I only recall seeing 2 but that was long time ago.

 

rears appear to be a monolythic catalytic converters, so I would agree with you 2 CATs...