[Banana_horse]

I’ve been feeling like my Hellcat has become a little sluggish lately. According to my Dragy, as much as half a second slower 60-130. No codes or anything but I did watch the AFR gauge on the dash during a pull just now and it seemed really low. Like consistently low 10.x and dips into the 9s. Shouldn’t it be much higher? Like almost 12? What can cause that?

Edit; the car is stock.

 

[ScLeCo]

That's pig rich. Belt slip?

 

[Banana_horse]

That's pig rich. Belt slip?

I'll look at it. But shouldn't the computer pull fuel if there's not enough air?

 

[Banana_horse]

I cleaned the MAF, and IAT sensors, no improvement.

 

[Banana_horse]

It seems to vary by gear, but at WOT in 5th (A8) it initially drops to ~11.9 but at 3.5k abruptly drops to low 10, as low as 9.5 I saw.

 

[baabootoo]

I guess I'd get some definitive info, like a dyno, before jumping to conclusions. A half second is like a heartbeat. Seat of the pants has never been accurate.

 

[Banana_horse]

I guess I'd get some definitive info, like a dyno, before jumping to conclusions. A half second is like a heartbeat. Seat of the pants has never been accurate.

You would have no concerns if you lost a consistent 0.5-0.7 seconds on your 1/4mi ET? Say from 11.1 to now an 11.6? Because that’s an eternity there. Even longer when I’m talking about going from a consistent 8.4-8.5 to 9.05-9.15 60-130.

 

[moparjim]

What year is the Hellcat?
Have you noticed boost dropping off and building back up?
Does the rich situation go away and come back on the same pull?
Have you had the car scanned with a proper scanner?

I ask because I was dealing with similar issues last year.
I got HPTuners to log and was able to see much of what was going on.

 

[Banana_horse]

What year is the Hellcat?
Have you noticed boost dropping off and building back up?
Does the rich situation go away and come back on the same pull?
Have you had the car scanned with a proper scanner?

I ask because I was dealing with similar issues last year.
I got HPTuners to log and was able to see much of what was going on.

Boost builds up to and steadies right at the edge of 9 and 10psi, flickers between them. When AFR drops from high 11 to 9 it stays there. I’ve only just started the investigation, so I don’t have scanner data, but there’s no codes or lights.

 

[furious70]

IMO you won't know anything until you're logging. A digital gauge on the dash may not tell you the story.
Totally different deal, but in my aftermarket efi on my fury the afr goes all over the place as the wide band helps it correct, but in like 1/4 second increments. So I'll see pig rich as it reacts to boost coming in.... For .25sec

 

[baabootoo]

I guess I wouldn't worry a bit, until I had definitive data. Hey could just have a tank of bad gas.

 

[Hpmaniac]

Stoich is not 14.7 on the hellcat. If I remember it's 13.85. So when you see 10.2 AFR it more like 11.0. There's some old threads talking about this. My redeye with stock tune would hit 9.8 afr. My new trx will also hit around 9.8 to ten flat. I use lambda now when tuning. 1.0 lambda is close to 14.7 afr and our cars when tuned make best power around .80 to .82 lambda.

 

[Banana_horse]

I have an OBD-II Bluetooth scanner thing that lets me track sensor readings in real time. What parameters should I be watching?

 

[Banana_horse]

Here's an example. Car is at temperature, running at idle.

 

[moparjim]

Boost builds up to and steadies right at the edge of 9 and 10psi, flickers between them. When AFR drops from high 11 to 9 it stays there. I’ve only just started the investigation, so I don’t have scanner data, but there’s no codes or lights.

Boost builds up to and steadies right at the edge of 9 and 10psi, flickers between them. When AFR drops from high 11 to 9 it stays there. I’ve only just started the investigation, so I don’t have scanner data, but there’s no codes or lights.

I just asked because I was having similar issues last year, that I blamed on the cat recall.
I did not have any codes in the car. With a dealer level scanner I had all kinds of random codes that didn't go together. One was lost communication with body control module.
Clear the codes and they would be back another time we checked.
I changed plugs trying anything to help my loss of power situation. The lack of consistency was a pain.
After plug change the car was good for a little while, then back to weird.🤔
The car was at the dealer this year and suddenly the car wouldn't charge. The it wouldn't restart. Lost communication with TCM this time. They were going to order a PCM. I asked them to check the grounds near the PCM and flash it. They found the ground post on the car the wires attached to was no good. Moved grounds and that fixed it.
Unfortunately it doesn't seam that you are having the exact same issues as I was.
A log would show more of what is going on.