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2019 Hellcat Redeye
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Discussion Starter · #1 ·
I'll try to keep the story as brief as possible...

I bought a Hellcat Redeye last July. It was bone stock. I eventually got a mid-muffler delete after about a month and drove it for several months without issue.

I took it to a track day in September. After a particularly long session, I was very low on fuel. During the cooldown lap, I switched it from Track Mode to Eco Mode to save fuel and it immediately threw the code for the active exhaust valve, passenger side. I took it to Dodge to have it fixed under warranty. I think they just reset the light, but their comment on the invoice says, "cannot diagnose due to aftermarket modifications." The only modification at the time was the mid-muffler delete - I hadn't touched the exhaust valves. So, I didn't understand why they said that. But the light was off and didn't come back, so I was happy.

This December, I put on the MFER-1 exhaust valve cutouts. I drove it for most of December without issue.

This past weekend, I had another track day. A similar situation as before where I went a little too long in the session and was running low on fuel. I forgot what happened last time, so I hit the Eco button. As soon as I did, the CEL light came on with P0420 (catalytic convertor/leaky exhaust/O2 sensor), P0430 (catalyst system efficiency below threshold), U133F, U1140 codes (both U codes are exhaust valve actuator codes with U1140 specific to the passenger side).

I got under the car today and checked the wires. I checked the MFER-1 install. I checked that the actuators still work properly. All seems to be in order, so I'm at a loss.

I know if I take it back to Dodge, they're gonna say, "can't diagnose due to aftermarket modifications." And I could take off the MFER-1 pretty easy, but they're still gonna say the same thing because of my mid-muffler delete. Regardless, a similar issue happened before I put on the MFER-1 and I drove with the install for about a month without issue - so I don't think it's the MFER-1 causing issues.

Do you guys have any idea where to start looking to fix this?
 

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I would start with your primary fuel pump. They don't last too long when you run them out of fuel- lubrication issue. I starved one on a V6 going up a steep hill while driving it in a spirited manner.
 

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2020 Dodge Challenger Hellraisin Scat Pack
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I'll try to keep the story as brief as possible...

I bought a Hellcat Redeye last July. It was bone stock. I eventually got a mid-muffler delete after about a month and drove it for several months without issue.

I took it to a track day in September. After a particularly long session, I was very low on fuel. During the cooldown lap, I switched it from Track Mode to Eco Mode to save fuel and it immediately threw the code for the active exhaust valve, passenger side. I took it to Dodge to have it fixed under warranty. I think they just reset the light, but their comment on the invoice says, "cannot diagnose due to aftermarket modifications." The only modification at the time was the mid-muffler delete - I hadn't touched the exhaust valves. So, I didn't understand why they said that. But the light was off and didn't come back, so I was happy.

This December, I put on the MFER-1 exhaust valve cutouts. I drove it for most of December without issue.

This past weekend, I had another track day. A similar situation as before where I went a little too long in the session and was running low on fuel. I forgot what happened last time, so I hit the Eco button. As soon as I did, the CEL light came on with P0420 (catalytic convertor/leaky exhaust/O2 sensor), P0430 (catalyst system efficiency below threshold), U133F, U1140 codes (both U codes are exhaust valve actuator codes with U1140 specific to the passenger side).

I got under the car today and checked the wires. I checked the MFER-1 install. I checked that the actuators still work properly. All seems to be in order, so I'm at a loss.

I know if I take it back to Dodge, they're gonna say, "can't diagnose due to aftermarket modifications." And I could take off the MFER-1 pretty easy, but they're still gonna say the same thing because of my mid-muffler delete. Regardless, a similar issue happened before I put on the MFER-1 and I drove with the install for about a month without issue - so I don't think it's the MFER-1 causing issues.

Do you guys have any idea where to start looking to fix this?
Well, the mods you have made to the exhaust would be my best guess.

The dealer is right in that it can't diagnose the problem due to changes to the exhaust. The factory exhaust has been tested and if the exhaust system in some way proves faulty the factory will agree to a warranty claim. In the case of the presence of modifications or aftermarket exhaust hardware, the dealer may be reluctant to attempt to diagnose the problem as it may not get reimbursed for its time or labor or any replacement parts -- new converters -- it determines are at fault.

My second guess is that the errors arise from the severe usage you give the car on the track.

Since the errors apparently only show up at the end of a particularly long session with the car low in fuel my advice would be to: 1) Put more fuel in the fuel tank. A few extra gallons is not going to materially affect your track time; 2) Cut your track sessions time; 3) At the end of the session don't engage Eco mode. Do give the car a cool down lap to give the heat load the engine/drive train and exhaust system have developed some time to dissipate before you park the car in the pits.

You can engage Eco mode when you subject the car to normal usage to see if there is something "wrong" with Eco mode to eliminate this as a possible source of the error codes.
 

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2019 Hellcat Redeye
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Discussion Starter · #6 ·
Apparently, I haven't been getting notifications for this post. Sorry I didn't reply to anyone.

I would start with your primary fuel pump.
It's not the fuel pump. It's exhaust related.

The dealer is right in that it can't diagnose the problem due to changes to the exhaust.
To say they can't diagnose something because of an aftermarket part doesn't sound right. Sure, I can understand if they won't warranty it, but for them to just stop work and say, "sorry, there's nothing we can do," isn't right. They could say, "hey, what's happening is XXX and that's because you have don't have a resonator - we can't do it under warranty, but it will cost you this much to fix." But still, resonator deletes and MFER-1 exhaust valve bypasses are very common and are known to not throw engine codes. Besides, two of the engine codes are cat related which are upstream of the resonators and the exhaust valve bypasses. So, I'm not sure how those mods can affect the cat.

1) Put more fuel in the fuel tank. A few extra gallons is not going to materially affect your track time;
I can't put in more gas than a full tank.

2) Cut your track sessions time;
I was cutting my track session short, but apparently not enough. Part of the problem is that the fuel gauge doesn't work exactly right when you're driving so hard. It'll read a half tank, but then you slow down coming off the track and it drops almost immediately to around 1/8th or less, sometimes the fuel light comes on. I was leaving the track when the needle read a half tank to avoid running out of gas - I still had enough left to get to the gas station that was about 5 miles away. But it was still a little too close for my comfort. I might just have to resort to counting laps from now on.

3) At the end of the session don't engage Eco mode.
I didn't mean to do it. It just slipped my mind. I won't be doing it again (if I can remember it). Though, that doesn't seem like a solution. I feel like the car shouldn't throw engine codes just because you go from Track Mode to Eco Mode after a track session. I'd prefer to know exactly why it's happening, but regardless, I'll try doing some cooldown driving before switching out of Track Mode from now on.

Follow Up:

The check engine lights went away on their own.

Like I said in my OP, I got under the car and verified correct installation of the MFER 1 system, I looked for any damaged wires, I make sure the connectors were properly seated, I cycled the power to make sure the exhaust valve motors were working properly, and I did a visual inspection of the exhaust system looking for damage and found none. I figured I'd get to an independent mechanic I know to get a better opinion on what's happening with the car and why these engine codes showed up before my next track day. But after a couple of days of just cruising around town, the check engine light went away. I'm guessing it has something to do with the O2 sensors reading out of range or not having the proper differences from upstream to downstream after the track day. Kindof annoying, but something I can deal with. I'm just happy it's all good now. :)
 

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2020 Dodge Challenger Hellraisin Scat Pack
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The diagnosis of a problem is covered by the warranty. In the case of the presence of the after market hardware this means very likely the dealer would not get compensated for its diagnostic time.

Additionally, diagnostic procedures are based on the behavior of the factory hardware. The after market hardware may affect -- probably does affect -- the behavior of other hardware in the system. The problem then becomes what is due to the after market hardware and what can possibly be attributed to the factory hardware.

The problem is the setup you have has not been extensively tested and makes the exhaust system an unknown. Just being downstream of the affected hardware is not enough to say the changes you have made can not account for the problems. The exhaust flow past the sensors/through the converters could be affected and differ enough from what is normal with factory hardware. That is the problem. The mods have not been vetted and thus make the performance of the exhaust system suspect.

The dealer can't be expected to be able to distinguish between what is abnormal behavior due to a problem not related to the presence of the aftermarket exhaust mods and what might be due to factory hardware.

You can't put more gas in a full tank but you I think realize that a hard running RE can go through gasoline at a ferocious rate and track session duration needs to take this into account. There is the fuel level but also the degree of heating of the fuel. My Porsche Turbo had a fuel cooler that when the A/C was on routed refrigerant to to cool the fuel to keep fuel temperature under control. The hard running pumps heated the fuel. The fuel returned picked up heat on its way from the tank to the engine compartment and back again.

P0420 and P0430 are converter operating below efficiency. This is determined by monitoring the #1 and #2 sensor voltages to confirm that extra oxygen in the exhaust gas comiong from the cylinder does not show up in the exhaust gas that has passed through the converter. The excess oxygen is supposed to be "captured" by the catalytic metals in the converter then during times there is a lack of excess oxygen in the exhaust to use this captured oxygen to process exhaust gases.

Under hard acceleration the engine controller is allowed to suspend its monitoring of converter efficiency. In part because under hard acceleration the engine controller needs to supply a richer mixture which while it helps the engine produce the power requested of it by the driver does not result in exhaust gases which are most efficiently processed by the converters.

The changes to the exhaust may effect how fast the converters can recover from the after effects of hard acceleration compared to how fast they can recover with the factory exhaust hardware. The engine controller is sensitive to this difference and the CEL and error codes are the result.

Under less severe operation while there could still be some difference in how the converters perform but they are still performing within spec.
 
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