Its not the older hellcats you need to worry about. Its the newer ones. The "Covid" cars. I had nothing but problems with my 21. Sold it a few months after I got it. The 21+ cars are going to have a much higher failure rate on parts due to QC being lowered on parts that would normally not make it on cars. But with part shortages all over the world, QC standards have been lowered and parts are getting through QC when before the shortages they would be labled FAIL.
My car had bad fuel pump, and both axles started leaking almost right away. After the fuel pump I still had some fueling issue that the dealer never was able to figured out. I turned to the aftermarket to see if a tune would help and learned some very scary things about the 21+ cars.
Mainly the Cat over temp thresholds and how the car acts when you hit those thresholds were lowered and sharpened substantially. The car is now programmed to basically dump all your boost and fall on its face if it hits the cat over temp. Which it will basically every time you make a pass or a pull. Verified all this with HP Tuners logs. I have several hours of logs and I made a thread about it here.
I have buddies with other 21 and 22 cars starting to see the same issue with cat over temp since summer is here now. I was seeing the issue over winter here in FL where it was still hot, but now that the rest of the country is in summer and guys are now going to the track, you are going to see more threads - "Went to the track and low mph" or "Car seems to be falling on its face at WOT"...
Its coming. You'll see.