[highwaymonster]

21 redeye charger , I put it on a dyno 620rwhp , afr 9.7 talked to a tuner and he said it’s called COT , told my my cats are heating up and the ecu is dumping fuel to cool them off , said it could be fixed with a tune. My problem is I don’t have all the parts I wanna install before I get it tuned so I was wondering if you guys think if I do a 02 sensor spacer will it stop it from reading such a high temp till I get my tune done

 

[FourDoorDemon]

Search @Vet Rider's post, he's a wealth of knowledge about COT, tuning, etc.

 

[Xylander]

Keep in mind that those high readings are a result of something going on that's causing the cats to heat up. Running too rich, for example, is a common cause. Disabling the cat cooling in the tune and/or putting spacers on will not prevent harm or damage to the cats. If it were my car, I'd either correct what's causing the cats to overheat (if what's going on is abnormal) or I'd quit driving it until my build was done.

 

[Jonx96]

Keep in mind that those high readings are a result of something going on that's causing the cats to heat up. Running too rich, for example, is a common cause. Disabling the cat cooling in the tune and/or putting spacers on will not prevent harm or damage to the cats. If it were my car, I'd either correct what's causing the cats to overheat (if what's going on is abnormal) or I'd quit driving it until my build was done.

Every redeye I have ever seen does this. You will not just simply fix the issue without a tune.

 

[Xylander]

Every redeye I have ever seen does this. You will not just simply fix the issue without a tune.

Most new cars have cat cooling built in... hence why I said in the parenthesis, "if what's going on is abnormal." You can disable that feature in the HP Tuner with a simple click of a button to turn it off... but then your cats will glow red hot and in a couple weeks they're dead, and in a few days your O2 sensors are fried.

 

[Vet Rider]

Every redeye I have ever seen does this. You will not just simply fix the issue without a tune.

Lol Thats exactly what fixes the issue.

 

[Vet Rider]

21 redeye charger , I put it on a dyno 620rwhp , afr 9.7 talked to a tuner and he said it’s called COT , told my my cats are heating up and the ecu is dumping fuel to cool them off , said it could be fixed with a tune. My problem is I don’t have all the parts I wanna install before I get it tuned so I was wondering if you guys think if I do a 02 sensor spacer will it stop it from reading such a high temp till I get my tune done

Yep its the dreaded COT changes that were made to 21 cars. Oddly enough I still havent seen any challengers with this issue, all chargers both redeye and normal HC.

Get a tune, they can turn up the COT thresholds so you never hit them. This is the only fix sadly. Thanks Dodge, a big class action lawsuit coming.

 

[FourDoorDemon]

Yep its the dreaded COT changes that were made to 21 cars. Oddly enough I still havent seen any challengers with this issue, all chargers both redeye and normal HC.

Get a tune, they can turn up the COT thresholds so you never hit them. This is the only fix sadly. Thanks Dodge, a big class action lawsuit coming.

You noticed what I did, that it only seems to be the Chargers, NOT the Challengers! WTF?! I know the additional heft is more load...I guess that's why?

 

[Vet Rider]

You noticed what I did, that it only seems to be the Chargers, NOT the Challengers! WTF?! I know the additional heft is more load...I guess that's why?

I spoke to Jeremy Satera today and he said he was seeing it across all platforms. Even TRX. So who knows.

 

[DuvShack]

I spoke to Jeremy Satera today and he said he was seeing it across all platforms. Even TRX. So who knows.

Just random cars, or is there a reason behind it? Curious to understand what's going on...

 

[Reaperhwk]

This is good info. I do not think it effects me for my use of the car(normal driving with a few highway pulls here and there). I do plan to take the car to a 1/4 mile track though. Will this effect my car if I make 2-3 passes? Between runs the car would be in the staging lanes cooling down.

 

[rayzazoo]

Just random cars, or is there a reason behind it? Curious to understand what's going on...

Emissions. Newer Hellcats/Redeyes already have the new CATs and software flash. Older Hellcats have a recall to flash update the PCM which lowers the CAT Overtemp Threshold temperature and change out the CATs.

 

[DuvShack]

Emissions. Newer Hellcats/Redeyes already have the new CATs and software flash. Older Hellcats have a recall to flash update the PCM which lowers the CAT Overtemp Threshold temperature and change out the CATs.

Thanks! Are they flashing it so the CAT overtemp happens more often, or less often?

 

[Vet Rider]

Thanks! Are they flashing it so the CAT overtemp happens more often, or less often?

Dodge has lowered the temp thresholds and increased the level of intervention that the ECM takes to protect the cats. Meaning it will kill more power, earlier than it used to when the cats reach the 1701* temp threshold. In reference, I have seen my stock cat temps show 1967* and a bit higher once this was all disabled and the car was able to run freely without intervention from COT. Thats a big delta from what the cats will reach to when the car will start to reel the power/heat back. Thats scary.

Before the newer version of COT was introduced, the temp threshold was still like 1749* I believe, but the level of intervention was much less when you hit those thresholds. Meaning it was far less apparent the car was protecting the cats when you were at WOT.

When I was hitting COT, my car was completely falling on its face. BAD. Bypass would open bleeding boost, AFRs would plummet to 10.0 and less and fuel pressure at the rail would also fall to 19PSI when it was commanded to be 80PSI. Then you'd see the injector duty cycle skyrocket to 130% when it was supposed to be like 70%. All of this would happen in real time when the car would absolutely fall on its face, and I could see all of it in my HP Tuners logs.

 

[ElBacano809]

Dodge has lowered the temp thresholds and increased the level of intervention that the ECM takes to protect the cats. Meaning it will kill more power, earlier than it used to when the cats reach the 1701* temp threshold. In reference, I have seen my stock cat temps show 1967* and a bit higher once this was all disabled and the car was able to run freely without intervention from COT. Thats a big delta from what the cats will reach to when the car will start to reel the power/heat back. Thats scary.

Before the newer version of COT was introduced, the temp threshold was still like 1749* I believe, but the level of intervention was much less when you hit those thresholds. Meaning it was far less apparent the car was protecting the cats when you were at WOT.

When I was hitting COT, my car was completely falling on its face. BAD. Bypass would open bleeding boost, AFRs would plummet to 10.0 and less and fuel pressure at the rail would also fall to 19PSI when it was commanded to be 80PSI. Then you'd see the injector duty cycle skyrocket to 130% when it was supposed to be like 70%. All of this would happen in real time when the car would absolutely fall on its face, and I could see all of it in my HP Tuners logs.

Which year was this protection introduced? Haven't heard of this

 

[Vet Rider]

It’s always been there. But for 21 they ramped it up.

 

[Bowlerguy92]

I believe you but I still have yet to experience this through normal operation and we've had some very hot days that I've pushed the car pretty hard in. It seems that my use case, at least, manages to stay below these thresholds where I might experience the issue so it's likely not something that many people will notice or run into, luckily. Maybe certain cars are worse than others as well for whatever reason but glad I'm not seeing it.

 

[moparjim]

Well my car did exactly like Vet Rider described after the cat recall and flash.
I only did it because I saw my car was going into cot protection stock. It did not seem to affect the performance at the time but it showed in logs. Mine is a 2016.
I had no choice but to tune out the problem.
My car is now back to being consistent and runs better than before. (We raised the shift points while tuning) Last weekend I got to run door to door with a Demon.😎

 

[Bowlerguy92]

I'd be curious to get Dodge's official stance on it. If it becomes a big enough issue there probably will be a class action since it doesn't sound like some of us are getting the performance that we've paid big bucks for.

Do other vehicles in the class have the same issue? GT500? ZL1? etc

 

[Vet Rider]

I'd be curious to get Dodge's official stance on it. If it becomes a big enough issue there probably will be a class action since it doesn't sound like some of us are getting the performance that we've paid big bucks for.

Do other vehicles in the class have the same issue? GT500? ZL1? etc

The GT500 has some sort of similar limp mode issue that plagues them stock.
I had an 18 ZL1 and now a 21 ZL1 and neither ever did anything like this. My current Z I have logged the hell out of. And aside from some random knock from being totally heat soaked, it has never did what the hellcats do at that degree. I mean with my 21 charger I was seeing 115mph traps at the end of the track. The car would rip to the 1/8 mile then completely die like the blower belt came off.