How To Choose a K-Series Map Sensor
Posted by Matthew Marks on 2nd Aug 2024
Choosing a K-Series MAP sensor is essential to ensure your engine's correct air-fuel ratio.
There are several different sensors on the market, and I will cover the most common ones so you can easily decide which one you need for your build.
We have a lot to cover here, and nowadays there are more options than ever to choose from! We will go through why each one is a good option, and how you can decide for yourself exactly which option to go with.
What Does a K-Series MAP Sensor Do?
A MAP or manifold absolute pressure sensor is designed to send pressure information back to the ECU. It is typically mounted on the throttle body or inlet/intake manifold.
They allow air through a vacuum line into the sensor, which pushes against a chip inside and will make it flex a certain amount depending on how much pressure is going into the sensor.
As this chip has a current running through it, once it starts flexing, the current change is given to the ECU via the wiring and will show the exact pressure rating here.
Once the ECU has this pressure data, it can add the correct fuel amount to ensure you get the proper air-fuel ratio to get the most efficient bang in the combustion chamber.
Why Should I Upgrade My K-Series MAP Sensor?
When you go with a turbocharged build with the stock Honda MAP sensor, you can only read up to 1.5 BAR, with 1 BAR of that being atmospheric.
So, when adding boost pressure, you must also increase the range the K-Series MAP sensor can read to allow for fuel adjustments.
This is where aftermarket options come into play and allow you to increase this sensor rating to whichever level of boost you decide to run.
Below, we will go through the most common options available from OEM 1.5 BAR up to aftermarket 7 BAR sensors and how to work out which one you need.
OEM K-Series MAP Sensor
OEM Honda K-Series MAP sensor is generally rated to 1.5 BAR, roughly the equivalent of 14.5PSI atmospheric and around 10.5PSI of boost pressure. However, I wouldn't recommend running any boost on a stock sensor.
A stock 1.5 BAR MAP sensor can accurately read from a vacuum to 10.5PSI over atmospheric pressure.
Once you start adding positive pressure (i.e. boost pressure), the OEM 1.5 BAR MAP sensor will not be able to accurately read this, so you must upgrade to a higher BAR-rated pressure sensor, which will adjust the fuelling correctly.
Suppose you have a naturally aspirated K-Series and want a replacement MAP sensor. In that case, a Genuine Honda MAP sensor will be a perfect option.
3 Bar And 4 Bar K-Series MAP Sensor
The next step up from OEM would be the aftermarket 3 or 4-bar K-Series MAP sensors. A vast number of companies are now making these, and we will compare a few below, but each one can read different levels of boost pressure.
A 3-bar MAP sensor can accurately read from around 1-29 PSI, whereas the 4 BAR map sensor can read from 1-43 PSI.
Some would think that because the sensor is rated to 4 BAR, it can read 4 BAR of actual boost pressure (59 PSI). The first BAR is atmospheric, so the 4 BAR sensor can only read 3 BAR of added boost pressure.
Most of the 3 and 4 Bar K-Series MAP sensor options are OEM fitment and completely plug and play, which makes installing one very simple and can be done in minutes.
5 Bar And 7 Bar K-Series MAP Sensor
As time passes, turbocharged K-Series builds get crazier, and people want more power.
As this power level increases, so does the boost pressure, so some manufacturers, such as Haltech, have created 5 and 7 BAR aftermarket options to allow for this.
A 5 BAR MAP sensor can read from 1-59 PSI, and a 7 BAR can read from a staggering 1-88 PSI!
Before we move into the best brands to go for, it's worth mentioning here that you will need an aftermarket ECU to read a high BAR-rated MAP sensor accurately.
In most aftermarket ECU settings, there is an option to add a specific BAR rating of the MAP sensor, so the ECU knows the correct scaling and can determine the fueling from here.
Which Brand Of K-Series MAP Sensor Should I Go With?
I will cover 5 of the most common brands we see daily regarding the K20/K24 MAP sensors.
Regarding how reliable they are, I have used most of these sensors and brands at one time or another, and they are all just as reliable as each other.
For transparency, the only sensor I have not personally used or tested is the K-Tuned 4 BAR MAP sensor.
There are options here from OEM all the way to 7 BAR.
I've added a table underneath this section to show the boost pressure you can run with each one, colour options and anything else worth knowing!
Genuine Honda
The first brand to go with for naturally aspirated applications would be the Genuine Honda MAP sensor.
Whether you need a replacement for your old inaccurate sensor or need to buy one for your build, they are the best OEM option.
They are mega reliable, as are all parts from OEM manufacturers!
Currently, at the time of writing, they are around £156, which is more than most of the options on this list, but with OEM fitment and quality, they are a good stock replacement option.
Speedfactory Racing
Speedfactory Racing is a massive Honda brand worldwide; its products show precisely why!
From a massive range of turbo manifolds and intercoolers to titanium bolt kits, they are a Honda lovers' dream.
They also offer 4-bar MAP sensor option for the K-Series, available in either red or black to suit the theme you're going for.
They are a solid option here, with the broadest range for OEM fitment, especially with the 2 colours to choose from.
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Skunk2 Racing
The next brand on the list would be Skunk2 Racing, which has been around since the 90s and, again, one of the biggest names in the Honda industry.
With products such as the Skunk2 Ultra Street intake manifold and Race series, they have created a massive product range over time.
They now offer a 3-bar and 4-bar k20 and k24 MAP sensor for direct fitment, but they are only available in black.
In terms of pricing, they align with Speedfactory and K-tuned for plug-and-play options.
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K-Tuned
K-Tuned is the last brand that offers a plug-and-play factory option but is only available in 4 BAR and black.
In terms of fitment, they are exactly the same as the other options and will still need to be calibrated in the ECU like the others.
They again follow suit for pricing and are a solid option when choosing a MAP sensor if the rest of their electronic range is anything to go by.
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Haltech
The last brand on this list is Haltech, which has the most comprehensive range.
You would always expect their range to be huge when they specialise in engine management systems and electronics, and their map sensor range is no different.
One thing to note about Haltech is that all of their options are universal, so they are not directly plug-and-play with a K-Series.
They have a wide range of MAP sensors, such as 3-bar, 4-bar, 5-bar, and 7-bar options.
They range from motorsport sensors to their 7-bar "TI" sensor, which must be remotely mounted to not cause damage to the sensor.
Suppose you are above the 43psi mark or want a solid, reliable sensor. In that case, a universal Haltech sensor is a great option.
The only downside to the higher BAR Haltech MAP sensors is the price, as they go up in cost with each increase, but it is worth knowing your car will work correctly at high boost levels!
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Comparing All Of The K-Series MAP Sensor Options
Now we've been through every option, it's time to put every single option side by side to see the best one for your application.
I've also included the maximum boost pressure you can run with each sensor in the table below. However, it's probably worth going with a higher-rated MAP sensor than your maximum boost level to account for sea level and scope in the future.
I've sorted them from the lowest to highest BAR rating to make it easy for you to choose one using the current boost level you are or want to run.
Brand/Product | Colour | BAR Rating | Actual Boost Pressure |
Fitment |
Genuine Honda 1.5 BAR MAP Sensor | Black | 1.5 BAR | 1PSI-10.5PSI | OEM |
Skunk2 3 BAR MAP Sensor | Black | 3 BAR | 1PSI-29PSI | OEM |
Haltech 3 BAR MAP Sensor | Black | 3 BAR | 1PSI-29PSI | DTM Connector |
Speedfactory 4 BAR MAP Sensor | Black or Red | 4 BAR | 1PSI-43PSI | OEM |
Skunk2 4 BAR MAP Sensor | Black | 4 BAR | 1PSI-43PSI | OEM |
K-Tuned 4 BAR MAP Sensor | Black | 4 BAR | 1PSI-43PSI | OEM |
Haltech 4 BAR MAP Sensor | Black | 4 BAR | 1PSI-43PSI | DTM Connector |
Haltech 5 BAR MAP Sensor | Silver | 5 BAR | 1PSI-60PSI | 1/8"NPT |
Haltech 7 BAR MAP Sensor | Silver | 7 BAR | 1PSI-87PSI | 1/8"NPT |
Frequently Asked Questions
There is a load of misinformation regarding MAP sensors and lots of questions.
Hopefully, I can clear up as many as possible here, but if you have any others you think would be helpful, please drop us a message in the comments section at the bottom!
What Does MAP Stand For?
MAP stands for manifold absolute pressure sensor but is also known as a manifold pressure sensor. Depending on who you are talking to, air pressure or MAP air flow sensor, though they are all the same thing.
Can I Drive With A Faulty MAP Sensor?
Although you can drive with a faulty MAP sensor in an emergency, I highly recommend against it if you can avoid it.
As the MAP sensor controls the fueling and shows the ECU the density of air going into the engine, once this reading is wrong, it can cause havoc and make the air-fuel ratio massively lean or rich.
This obviously depends on how far out the sensor is reading. Still, it isn't worth risking when it can blow an engine or go into limp mode.
Not only this, but the poor air-fuel ratio can also decrease the life of a catalytic converter and cause a lack of power, etc.
Is a MAP Sensor Plug and Play?
Most of the MAP sensors on this list will physically plug in, but you will need to adjust the MAP sensor settings on the ECU, so it knows the scaling for the sensor.
For example, suppose you have a K-PRO and a Speedfactory 4 BAR MAP sensor.
In that case, you must go into the settings and select the correct BAR rating for the MAP sensor, scaler, and offset, which are usually included in the product listings or installation manuals.
Can I Clean My Old MAP Sensor?
Yes, you can clean a MAP sensor, but use something that will evaporate, such as a brake cleaner or a specific air sensor cleaning spray.
Do not use something such as WD40, as this will leave residue and potentially make the sensor more inaccurate.
Let the MAP sensor dry entirely before installation, and you're good to go!
Can I Go Too High On The BAR Rating?
This is a widespread question when choosing which MAP sensor to use, and the simple answer is no.
Although you should always leave some headroom for the MAP sensor to work correctly, you also aren't going to do damage by having a higher BAR sensor than you'll ever need.
The best way to choose one is to decide which boost level you're running, add 20% and work out the closest MAP sensor above this number.
For example, if you run 2.2 BAR of boost pressure plus the atmospheric 1 BAR, you will have 3.2 BAR. You should then go with a 4 BAR MAP sensor to leave you with a bit of headroom and be able to measure pressure accurately.
There is no need to run a vast 7 BAR sensor if you only run a BAR of boost. In reality, any aftermarket ECU nowadays has enough resolution to make it work correctly.
Conclusion
So there we have it: my best brand picks and comparisons between the most common MAP sensors for a K-Series.
Hopefully, you have learned something new and can now decide on the exact MAP sensor you need for your application. You can also spec the MAP sensor according to the boost level you are running at.
If this has helped you, please leave a message in the comments section below. If you still have questions, please head over to our contact form.
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Also, if you want to learn more about the K-Series or EP3, check out some of our related articles and guides below: