[?] '18 Intake Manifold on '15-'17

kwikS550 said:

Yeah the same thing crossed my mind about throwing the code for both banks.

I really don't know, but it's a lead and worth a try. Hopefully I can give it a shot tonight.

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So you're running the PP2 tune correct? Are the other guys in here that are having CEL issues running stock or PP2 tunes as well? I'm guessing that's the issue because when I talked to Lund they assured they could tune for the manifold with the IMRC's functional and not have any CEL issues.

Do you think if you switched tunes it would solve your problem?

S550MG said:

So you're running the PP2 tune correct? Are the other guys in here that are having CEL issues running stock or PP2 tunes as well? I'm guessing that's the issue because when I talked to Lund they assured they could tune for the manifold with the IMRC's functional and not have any CEL issues.

Do you think if you switched tunes it would solve your problem?

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Yes, I'm running a PP2 tune. I imagine the IMRC tables in the PP2 tune are the same as the stock tables since it's the same IMRC hardware.

Yes, there's no question that tuners can swap in the 2018 IMRC tables so they work or just turn off the IMRCs altogether.

The question is can the 2018 manifold be swapped onto a car without any tuning, make power, and not throw any codes.

kwikS550 said:

Yes, I'm running a PP2 tune. I imagine the IMRC tables in the PP2 tune are the same as the stock tables since it's the same IMRC hardware.

Yes, there's no question that tuners can swap in the 2018 IMRC tables so they work or just turn off the IMRCs altogether.

The question is can the 2018 manifold be swapped onto a car without any tuning, make power, and not throw any codes.

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At this point id just run the lo lockouts man.

re-rx7 said:

At this point id just run the lo lockouts man.

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Or go with an aftermarket tuner. At least that way you know you’re maximizing the power potential of the new manifold.

BULL1TT said:

So I'm looking at a datalog from my car. The stock imrc sensor sends a signal of 1.12 volts when it is closed and 3.96 volts when it is open. Now we just need to know what a 2018 signal is. Maybe it sends a lower voltage when open and the ecu is thinking that it is closed because it never sees the 3.96 volts that is required to be open.

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I have 2018 GT that I’m currently datalogging with Lund for my flexfuel tune. When my IMRC is closed, it’s sending a voltage of 1.411. When open, it’s 3.33 volts. Hope this helps.

re-rx7 said:

At this point id just run the lo lockouts man.

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I can tell you that the ‘18 motor opens the IMRC at around 1600rpm during WOT. By going to lockouts, you are probably not going to notice any adverse drivability issues on max effort setups.

But, during non-WOT events, the IMRC stay closed until 3600rpm at which point they open even at low throttle commands. Again, this is happening with ‘18 ecu and ‘18 manifold.

guys just do the lock outs slight difference in Tq in 2nd gear low end past that nothing with cai, exhaust and the 18 manifold I'm running 510hp to the crank which is about 450whp. no dyno yet this is a ball park number my buddie has 430whp and I was pulling on him

GTBOB said:

I have 2018 GT that I’m currently datalogging with Lund for my flexfuel tune. When my IMRC is closed, it’s sending a voltage of 1.411. When open, it’s 3.33 volts. Hope this helps.

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Interesting. Does anyone know what the ecu needs to see on a 15-17 in order to know that the imrc is fully closed?

Maybe the 1.41 volts that the ecu is getting when closed is too much and the ecu thinks that the imrc are only partially closing. That may explain the P2005 code for the imrc being stuck open.

kwikS550 said:

When I was looking into what could be causing the P2005 code I read that the PCM doesn't just check the function of the IMRCs signal at face value, it does some backend calculations off other sensors like TPS, coolant temp, O2, and RPM to make sure everything is in spec.

What I'm afraid of is that the airflow from the 18 manifold is enough to throw off the backend calculation enough to throw a code.

This is just a theory.

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Does anyone know if the gt350 intake throws the p2005 code? It uses the same imrc setup as the 15-17. If it doesn't throw this code then it has to be the imrc sensors output and has nothing to do with the additional flow from the intake. If the gt350 intake does indeed throw the same code then it looks like it may be a tune only mod.

BULL1TT said:

Does anyone know if the gt350 intake throws the p2005 code? It uses the same imrc setup as the 15-17. If it doesn't throw this code then it has to be the imrc sensors output and has nothing to do with the additional flow from the intake. If the gt350 intake does indeed throw the same code then it looks like it may be a tune only mod.

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That’s a brilliant question. Cutting the Gordian knot stuff right there, legit.

I started my install tonight. Got one of my connectors soldered on and ran out of steam. I’m gonna finish it up in the morning. I can’t wait to drive this beast tomorrow.

I’m taking lots of pics of the wiring and vacuum lines and I’ll be posting an in depth write up on the install in a few days. Overall it’s not as hard a job as I thought it would be.

S550MG said:

I’m taking lots of pics of the wiring and vacuum lines and I’ll be posting an in depth write up on the install in a few days. Overall it’s not as hard a job as I thought it would be.

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Thank you. Much appreciated.

I got notification that my '18 IM from White Bear Lake Ford is on its way...

So I believe I found the issue that's causing the P2005 code. I'll give a little technical information first.

The sensor that detect if the flaps are opened or closed put out a voltage that the ECU reads and determines the state of the flaps.
These sensors are the 3 pin connectors that are separate on the 15-17 IM and integrated on the 18 IM.
The voltages I'm going to be referencing are rounded and will vary from car to car slightly.

I looked at datalog I took with my 2015 IM and the IMRC Sensors are putting out 1.16v when they are closed and 4.00v when they are opened. On the 2018 IM the sensors are putting out 1.45v when they are closed and 3.39v when they are opened. Now this is causing a issue because while driving around the ECU is looking for 1.16v to verify that the IMRC's are fully closed but instead they are getting 1.45v which makes the ECU believe that the IMRC's aren't fully closing. Because it detects this issue it will revert to a permanent open state and give the P2005 code that they are stuck open because it never seems them as fully closed.

Now for possible solutions. I don't know if the voltage that the ECU is looking for are adjustable in the the tune. If they are then the tune will just need to be adjusted to the new voltage's that way the ECU correctly determines the state of the IMRC's. The other solution would be to add a resistor in the wiring harness to reduce the 1.45v to 1.16v that the ECU is expecting to see. The possible issue with doing this is that the open voltage, which reads 0.61v low on the 2018 IM, will be even lower which will make the ECU think that the IMRC's aren't opening all the way.

Tomorrow I plan on trying the resistor method with the adapters that I'm developing and we'll see if the ECU is happy once I bring the closed voltage closer to the original reading.

I wonder what the comparison in voltage for a GT350 tune, if it's close or still needs to have the voltage adjusted. Good info from EODTech87

Kahboom said:

I wonder what the comparison in voltage for a GT350 tune, if it's close or still needs to have the voltage adjusted. Good info from EODTech87

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The GT350 IM appears to use the same sensors that the 15-17 IM uses which would mean that the voltage is the same so no adjustments will be needed.

I'm pretty confident that tuners will be able to adjust the target voltages so that everything will work correctly. Only reason I'm going to try the resistor method tomorrow(Which I don't think will work) is because I have plenty of extra parts, since I ordered enough to make 20 sets of adaptors, and I'm impatient and want to get my car running correctly but Lund isn't open until Monday.