10 Myths about Chipping Honda ECUs

I like to think I am a “middle ground” Honda ECU tuner. I wasn’t quite there in the beginning, but I certainly didn’t just jump on board. I’ve helped many tuners get going with modifying their Honda ECUs, from doing the physical soldering, to fine tunning the final product. I spend a lot of time on Honda message boards, and I’ve seen my fare share of mis-information both presented and followed by beginners. I’m here to try and clarify some of the myths iv heard over the years.

10. I have to have my Honda ECU tuned by a professional, on a dyno.

False. I know of many average, everyday tuners (including myself) who have tuned there own Honda ECU from start to finish. That includes soldering, creating a basemap, adjusting idle, and fine tuning for boost, without any help from a “professional”. Tuning a Honda really isn’t very difficult, but it does take time and patience. Don’t expect to have your car running at all, never mind smoothly, the first time you head out to tune. Tuning is a constant process, its very difficult to account for every variable in a single dyno or street tune. Things like temperature, altitude, and humidity can all effect your tune, and its unlikely you will find a wide variance in any of those in one outing. So have a little faith in yourself and learn something new, you cant beat the rewarding feeling you get from tuning a car yourself.

9. Honda ECU Tuning is only for turbocharged cars

False. Not only can you tune a modified naturally aspired car, but you can even reap benefits from tuning a completely stock engine. Honda, and all other car manufactures provide extremely conservative fuel and ignition tuning on their stock vehicles. Think about what they are trying to accomplish: Providing a single tune that can account for every possible situation, in all temperatures and altitudes. This is a little easier to do with a mass air flow sensor (M.A.F.) because you are measuring the exact number of air molecules, which is why you see many factory turbocharged cars utilizing them. However, most Honda’s, especially pre-2003 use a manifold absolute pressure sensor (M.A.P). M.A.P. sensors measure the pressure of the air, not the density, so there is a lot of room for error. Advancing the ignition and leaning the Air/Fuel ratio out on a stock engine can yield moderate gains. Just be careful you dont go too far, everything in moderation. Don’t expect a 30whp gain.

8. Soldering a Honda ECU is difficult.

False. When i started modifying Honda ECUs, i had zero electronics or soldering experience. I drove myself to Radio Shack, where i picked up a basic soldering iron, desolering iron, and a roll of thin solder, ordered a Moates Honda ChipKit, and surfed over to the fantastic pgmfi.org wiki and read their introduction to ECU chipping article. Within an hour I had everything desoldered and the new components soldered in place. I didn’t even have to look for any soldering tutorials, as i figured it out pretty easily. I then did a search on xenocron.com’s fantastic basemap library, where i found a pre-made map that was close to my setup. I burnt the chip using my Moates Burn1, popped the newly chipped Honda ECU in the car and fired her up. SUCCESS! My point here is that if a no-name, clueless noob like myself could figure it out, there is no reason you couldn’t do it either.

Here is a list of resources:

7. You can’t tune a Honda ECU without an Ostritch

False. The famous Moates romulator, Ostritch ,didn’t always exist. There was a time when we were forced to tune without them. How did we ever get anywhere without real time tuning!!?? The answer is patience. There is no debate that a romulator makes tuning 100x, 200x, 1000x easier, but its not a necessity. You can get just as good of a tune with a simple chip programmer and a little bit of patients as you can with an Ostritch. I have personally never purchased a romulator (though I have used them), and i got by just fine. The key is to try and get as much data as possible between each run, since you will be stopping the car, turning it off, burning a new chip, and fireing it up again every single time. It can be tedious, but it saves $175.00.

6. I need a missing link, or else i’ll throw a CEL (check engine light).

False. This is something i hear more often than you might think. “I need to get one of dem missin’ links right? or my ECU be throwin’ codes n shyte”. The answer, quite obviously (or so I thought), is NO. You do not use a missing link with a chipped Honda ECU. The missing link was used back in the early days by guys using rising rate adjustable fuel regulators. The problem was that the Honda ECU would read a positive manifold pressure and not know what to do with it. A check engine light (CEL) would ensue, and all hell would break loose (not really, but we needed some drama). By the time the Honda community moved onto using the famous “AFC Hack”, the missing link should have been a thing of the past. With both the AFC hack, and a chipped Honda ECU, the ECU needs to read positive manifold pressure in order to work. No positive pressure reading, no work. Plain and simple. Using a missing link with the AFC hack or a chipped Honda ECU will make things much worse, and you will be pulling your hair out trying to figure out what is wrong.

5. Im only going to run 5-7 PSI, so an AFC will be fine.

False. Luckily this kind of mentality is dwindling away in the Honda community thanks to great advances in Honda ECU tuning software, but I still hear it on forums once in a while. The age old AFC hack should never be used anymore. I dont care how many PSI you want to run, or if your running naturally aspired, the AFC is inferior in every way to a chipped Honda ECU. Remember, the AFC hack (and its called a “hack”, for good reason) is tricking the ECU into thinking there is a different manifold pressure than there really is. This, in turn, causes the ECU to compensate and add/subtract fuel accordingly. Why would you ever want to trick the ECU, when you can tell it straight up whats really going on? Chipping a Honda ECU modifies the actual firmware, or computer code, telling the ECU that positive pressure exists, and to be ready for it. The cost of an AFC is still in the $150 range, and with that you can have a fully chipped and working ECU.

4. I cant use a chipped Honda ECU on an OBD2 car.

False. Just because you can’t physically chip an OBD2 ECU (at least not in the sense you can with OBD1), does not mean its impossible to run a custom programmed ECU. All that needs to be done is an OBD2->OBD1 conversion, using one of the many, pre-made, conversion harnesses. This allows you to run an OBD2 car, or engine, from an OBD1 computer, including chipped or modified OBD1 computers. Check out www.rywire.com for their OBD2a/b->OBD1 conversion harnesses. Make sure you figure out if your ECU is OBD2a or OBD2b, as this will make a big difference.

3. The p06 is the only Honda ECU i can use.

False. I’m not sure how this rumor got started, maybe its just because the p06 is so common, but i hear all the time “I need a p06 ECU for my car”. This is especially rampant among accord owners, who cannot use their factory ECUs like civics or integras. The fact of the matter is this: You can use just about any OBD1 civic or integra Honda ECU. This is NOT limited to the p06 or p28. I have personally used:

Shall i continue? All of these Honda ECUs are very, very similar in design, and only minor changes need to be made to make them work (For eample, the p05 needs to have an o2 heater circuit disabled in Crome).

3.5 If I have a VTEC Engine, I need a p28 ECU

I didnt want to give this myth its own number because its closely related to #3. It seems that a common misconception about the p28 is that its the only VTEC ECU available. Aside from the fact that the P72 is also a VTEC ECU, its important to note that most of the non-vtec ecus can actually be converted to handle a VTEC engine with a fairly simple hardware modification. More details about the conversion itself can be found on the pgmfi.org wiki. The electronic components you will need can be purchased from Xenocron.com.

2. Hondata is better than Crome

I wont give a definite ‘False’ on this one, as the subject is up for debate. However, i hear this a lot on message boards: “Hondata is much better than Crome, because Crome is free”. Thats like saying Windows is better than Linux because you can get linux free of charge (Thats a topic for a whole ‘nother blog) . There seems to be a big misconception that Hondata is superior, simply because it is proprietary. I’ve used both Crome and Hondata, and i can honestly tell you there is not a whole lot Hondata can do that Crome can’t, especially for the average tuner. Crome has a ton of advanced features, including data logging and real time programming. An average tuner would never use some of the more advanced features of Hondata. One thing to note about this, is that Hondata seems to have the market share when it comes to OBD2 ECU modification. The “K-pro” unit from Hondata is the be all end all for K-series engines, nothing else can really come close.

1. I can just use this basemap i found online

FALSE! False. false. It seems that the biggest myth of all is one that is more implied than spoken. I have probably seen literally 100 beginning tuners do this. They find a ‘Basemap’ on the internet, burn it to a chip, start their car up and beat the shit out of it. This is the worst thing you can do. Running for extended periods of time on an untuned map can severely damage your engine. Remember, every engine is different. Even if they are the same model, they have probably led very different lives. Some engines may have been used by an 80 year old Sunday cruiser, while another was beaten to hell by a 16 year old douche bag. Two engines of the same build can sometimes have a 20whp output difference, stock for stock, simply due to the condition of the engine. Engines in poor condition are going to need different tuning than those in good condition. Just the difference in compression ratio alone can account for a significant variance in Air/Fuel ratio. This is besides the fact that you sometimes have no idea who made the basemap you have, whether they were reputable, what modifications then may have to their engines, or if they even did significant tuning in the first place. The last thing you need is a recycled, untuned basemap of unknown origin running your car. So keep your head straight, and think about what you are really doing when you chip your Honda ECU. A little forward thinking can save you an engine swap.

Disclaimer:

The information presented in this article is the thoughts and expressions of the Editor. The information may or may not be 100% accurate, and DigMyHonda.com takes no responsibility for any harm that may occur from the suggestions presented. If you feel any of the information presented above is inaccurate or missing, please email lostshootingstar@gmail.com and the subject can be discussed.

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