CAI throws P0402??

[AirRyan]

Spot on! It's all about flow and not peak boost numbers. As stated above if the ECU detects to much air flow or to little air flow it throws a fault code. There are a handful of members on here that run the S&B and they do not throw codes. I am guessing the Banks is allowing a little to much air in resulting in a code. THis has been a known issue with Banks ever since they introduced the CAI for the 19+ trucks. The fact they do not have a solution would be concerning to me as a buyer. Is anyone with a tuned 19+ truck running a Banks CAI? If so are you throwing any check engine lights?? I am assuming with tuning you will not have any issues but its very expensive especially for the 22+ trucks (over 4k!!).

But the issue isn't airflow measured by the MAF on the CAI, it's EGR excessive flow, which is much further down the line on the EGR - on the complete opposite end of the engine compartment from the MAF on the CAI.

Quite frankly, it doesn't make any sense that the CAI even has anything to do with the EGR flow. Air first comes into your air intake, goes past your MAF, (which if the flows were excessive there it would trip a different code), and into your turbo on the pax side of the motor, then out the turbo and into your intercooler via the hot side boost tube, through the intercooler in front of the radiator on the front of your truck, and then through the cold side boost tube into your intake manifold, of which your EGR sits on top.

Just doesn't make a whole lot of sense that the MAF on the CAI isn't throwing a code but the code for EGR excessive flow is tripping.

Is anyone getting these codes have the Banks Moster Air Ram installed, and/or boost tubes installed, as well?

 

[AH64ID]

If the intake flows more air then it’s going to draw more EGR air with it for the same EGR valve position.

 

[Riddick]

More air in equals more air out. If you bring in more air it effects the entire system from intake to exhaust which includes the EGR.

 

[AirRyan]

However much more air the Banks CAI is pulling, it's not pulling enough to trip the usual suspect for a CAI, which is a MAF code for being too lean. The P0402 code means that the engine is not being leaned out and running too lean. I'm new to the Cummins but my experience with GM LS and LT motors, they come notoriously rich from the factory for a variety of reasons, so when you typically add a CAI the fuel trims can adjust for the increased flow without tripping a code for being too lean.

 

[AH64ID]

You can’t compare gas lean/rich issues to a diesel, they don’t work the same in terms of an air:fuel ratio.

 

[SpeyRam]

I installed the Banks CAI in the Spring and it threw the code a few times and has since stopped even with a good amount of driving/towing I've been doing the last few months. I really wouldn't worry about excessive EGR flow and its impact on the life of the motor. I agree with the principles of Banks products (increase mass air flow) but they are likely more marketing than function. That being said, I do like the Banks intake horn for the stock grid heater bolt delete.

 

[AirRyan]

You can’t compare gas lean/rich issues to a diesel, they don’t work the same in terms of an air:fuel ratio.

The F they don't?! Where did you get that from? Combustion is combustion. Air plus fuel added with either a spark from a gas motor or compression on a diesel produces combustion. You can't get combustion without air and fuel. The stoichiometric air-fuel ratio is about 14.7:1 for gasoline motors and maybe about 14.5:1 for diesel.

Listen to the 5:05 mark where Gale Banks is talking about the air/fuel mixture ratio when they tune their diesel motors.

 

[AH64ID]

The F they don't?! Where did you get that from? Combustion is combustion. Air plus fuel added with either a spark from a gas motor or compression on a diesel produces combustion. You can't get combustion without air and fuel. The stoichiometric air-fuel ratio is about 14.7:1 for gasoline motors and maybe about 14.5:1 for diesel.

Listen to the 5:05 mark where Gale Banks is talking about the air/fuel mixture ratio when they tune their diesel motors.

Yes combustion is combustion, but diesels don’t run a constant air:fuel ratio like a gas. Diesels don’t run at stoich. It’s constantly variable. Air flow is not regulated to keep the air:fuel ratio at a specific number on a diesel, the engine gets as much as as it wants (aside from some emissions flow restrictions for mixing EGR). So it’s not the same and don’t think of it the same as gas.

 

[AirRyan]

Yes combustion is combustion, but diesels don’t run a constant air:fuel ratio like a gas. It’s constantly variable. Air flow is not regulated to keep the air:fuel ratio at a specific number on a diesel, the engine gets as much as as it wants (aside from some emissions flow restrictions for mixing EGR). So it’s not the same and don’t think of it the same as gas.

You don't tune any engine for a constant AFR. But we're getting off track. You're not getting a lean code, you're getting an EGR excessive flow code. Your engine isn't running lean.

 

[AH64ID]

You don't tune any engine for a constant AFR. But we're getting off track. You're not getting a lean code, you're getting an EGR excessive flow code. Your engine isn't running lean.

Gas engines run a much more constant AFR and also monitor it, diesels don’t.

You’re the one who said it was running lean, I’m just pointing out you can’t think about it the same way on a diesel.

 

[AirRyan]

Gas engines run a much more constant AFR and also monitor it, diesels don’t.

You’re the one who said it was running lean, I’m just pointing out you can’t think about it the same way on a diesel.

But what you are saying doesn't make any sense to me. Have you ever tuned a motor or watched someone who has? Have you seen the chart in HP Tuners, there is not just one AFR number. Your AFR is not static and what you are trying to convey in that a diesel motor doesn't run rich or lean makes no sense to me. Diesel combustion is the result of the compression in the cylinder versus a spark in a gas motor, but I'm otherwise not sure what you are trying to get at.

Part of the reason I am sure why Banks has not resolved this issue yet is because it is intermittent and hard to replicate. None of the vehicles that Banks sees in their shop where they install their parts ever produces these codes. Of course, most of the vehicles who come in there usually get all their parts available so that would mean the Monster Ram Air intake and boost pipes, as well, on the 6.7 Cummins.

With the case of the Banks CAI on the L5P Duramax, it was creating for too much flow past the MAF and tripping a (lean) code, which is why they had to come up with their patented air mass control module, so they could fool the ECM without otherwise tuning it. That won't work here because the code being tripped isn't coming from the MAF, it's coming from the EGR.

Is anyone getting this code with this Banks CAI, also have the Banks Monster Ram air, (or any other aftermarket intake manifold, for that matter?) Banks testing claims 88% greater flows vs stock and they haven't been tripping any EGR codes with that. Not saying the P0402 isn't an issue, just trying to explain why this issue has been hard to track down.

The stock grid heater is a weak point and that nut could brick your entire motor if it ever fell off, so it's not exactly a bad idea to delete that and go with something like the Banks Monster Air Ram intake which is CARB approved and still retains a coil heater for cold climates.

 

[Riddick]

I'm pretty sure @AH64ID has spent a good amount of time behind the keyboard tuning Cummins platforms. Gas and diesel engines are vastly different.... I was blown away when I realized diesel engines don't have throttle bodies. They get ALL the air and are primarily controlled with fuel.

Why do you keep referencing a CAI for the L5P that caused a lean code? No-one on here has reported this on a Cummins so not sure why you keep referencing it. Also, their "patented air control module is simply a hack job and is tricking the ECM. The correct way would be to modify the MAF transfer tables to compensate for the increased air flow. Be very careful of devices that intercept stock signals tricking the ECM. I would advise to find a company who specializes in tuning so the ECU sees true data and adjusts accordingly. Intercepting stock signals and tricking the ECM will only cause headaches later down the road.

 

[AirRyan]

I'm pretty sure @AH64ID has spent a good amount of time behind the keyboard tuning Cummins platforms. Gas and diesel engines are vastly different.... I was blown away when I realized diesel engines don't have throttle bodies. They get ALL the air and are primarily controlled with fuel.

Why do you keep referencing a CAI for the L5P that caused a lean code? No-one on here has reported this on a Cummins so not sure why you keep referencing it. Also, their "patented air control module is simply a hack job and is tricking the ECM. The correct way would be to modify the MAF transfer tables to compensate for the increased air flow. Be very careful of devices that intercept stock signals tricking the ECM. I would advise to find a company who specializes in tuning so the ECU sees true data and adjusts accordingly. Intercepting stock signals and tricking the ECM will only cause headaches later down the road.

See, now you're not making any sense. Primarily controlled with (diesel) fuel as if air is constant and equal? What is the turbo for again?

Regardless. The reference to the L5P is to point out that a lean code from a MAF on a CAI is entirely different from the EGR excessive flow code some of you all are talking about here. The Banks air control module is not a hack job, it was produced in lieu of having to otherwise tune your ECM. L5P's have never been cheap to tune due to the increased encryption on the ECM's. Nobody is going to otherwise install (just) a CAI that requires a tune. This is why Banks may have said to some experiencing this issue that the engine isn't in danger with this code (because it's not running lean.)

 

[Jneely1076]

I have a 2020 ram 6.7, s&b intake, and tuning from Duramax tuner. Ran for 20k miles with that intake and tune with no issue. Installed Banks Intake horn and boost tubes, towed for about 400 miles and started getting an under boost condition.

Swapped tmaf sensor on intake horn, boost issue went away but started with a plethora of other codes.
P0106
P24A5
P04DE
P0234
P0401
P0402
P24A5
P04DE
P040B

All at different times. Pulled the EGR valve, visibly had gotten hot and discolored from the outside. Replaced the valve, truck was running great.

About 6 different 8 mile drives it was good, then an early morning start and drive to work, 4 miles in and cold outside, low throttle no load
P0402
P04DE
P0401

Re set and drove again, about 3 runs to and from work, another cold morning
P04DE
P0402

Re set, drove great all day, next morning cold start, didn’t even get out of my neighborhood
P04DE
P0402

I have no idea where to go with it at this point. Dealer has reflashed the computer twice, I have no doubt the egr valve and tmaf sensor were bad previously. Maybe the sensor was toast from the valve being stuck open? But now what? Are these all a symptom of something down stream?

I like the banks parts but wishing I hadn’t spent a dime on them if they kicked off this mess. The “D” is sounding better, but I’d rather not. Truck only has 38k miles, but the dealer was kind enough to tell me I’m 2k miles outta warranty. Truck is in Oregon or I’d be at Banks letting them study all they want.

 

[Jneely1076]

I should say the plethora of codes happened after swapping the sensor then trying to tow my 11k lb trailer to the coast over 4 mountain passes 300 miles, then on the trip home it threw me into limp mode with the codes. NOx code too.

 

[AirRyan]

I should say the plethora of codes happened after swapping the sensor then trying to tow my 11k lb trailer to the coast over 4 mountain passes 300 miles, then on the trip home it threw me into limp mode with the codes. NOx code too.

Make sure you talk to Banks and give them all those codes and information. Doesn't make sense to me that the only variable there is just the CAI but if you don't share with them it's that much harder for them to troubleshoot.

 

[Synolimit]

Well that’s annoying. Just bought one and it’ll be here Friday. Other cars have issues too, I guess it’s the time we live in now!!

I put a CAI on my 2022 Camaro and all i did was unplug the MAF and swap it over to the new tube and plug it back in (car off of course.) Unplugging the MAF sent it into a hard limp mode. No matter what we did we couldn’t get the code to clear. Luckily my dyno guy had two versions of HP tuners. The second laptop was able to clear the code after an hour trying to figure it out. The cars not tuned, all stock besides the CAI and all we wanted to do was see a before and after dyno to see if it added HP (it added a lot of HP). But it goes to show you! In 2022 on these new cars, the manufactures aren’t playing around and they don’t want the cars touched!!! I’m sure there is a digital log of me messing with the MAF and GM will probably use that to deny a warranty.

Out of curiosity, did everyone here unplug the 2 sensors on the intake and swap over or leave them plugged in and swap over?

 

[Synolimit]

Also, on a side note, Hardaway Performance out of Florida just posted about a week ago now that they can unlock your ECU with HP Tuners and tune up to a MY24 Ram Cummins, so hopefully if it's just a lean issue with the Banks CAI they can get that sorted out sooner rather than later. Usually, motors are set from the factory very rich and that is why a CAI usually doesn't throw a code saying it's too lean when installed.

Hardway Performance

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I don’t think that really counts. You’re replacing your ECU with an older one. That’s not unlocking your 22+ ECU that’s encrypted.

 

[mostfrantic]

Just wanted to add, I have the SB Filters CAI and it throws this code as well. (22 ram 2500, around 8k miles)

 

[arob]

Hi guys....new here but wanted to say that I have 2020 Ram 2500 6.7L. I put Banks CAI on about 4 months ago and no problems. I just recently added the Banks boost pipes about a week ago. The weather just turned cold (40-50 daytime, low 30s nighttime) and I've had engine light come on last 2 days. First was P0402 and today was P04DE. I have a Banks IDash so I cleared the code but the engine seems really sluggish and fuel mileage has taken a dump. Was getting 18-19 daily but now its down to 13-15. Based on reading previous comments, I'm now worried I wasted $$$.