This Technical Checklist was designed with HHO users in mind. Sometimes HHO Systems bug-up a little, but are usually easy to fix. If you are having trouble with your HHO System, or aren't seeing the gains you should be seeing, follow these steps to hopefully narrow down the problem, and solve it. These steps have been ordered in the manner they are, so that the most likely problems are higher on the list. You should work these checklist items form the top down. The problems that are easier to test appear higher on the list, and are also less expensive to fix. We are all about saving money, so make sure the higher issues are cleared out of the way before getting into costly vehicle maintenance. However, a well-maintained vehicle will always provide the best possible results with an HHO System attached to the engine.

The simplicity of what we have to do, to have a successful HHO installation, is:

a) Introduce HHO into the engine, and
b) Adjust the sensor inputs, as necessary, so the ECU is not blocking the gains.

That's all. If we can do those two things, we will always get vastly improved fuel economy and much cleaner emissions. We are striving to use HHO as, not only a fuel economy source, but a greener technology for a greener tomorrow.

The thing you have to realize is that this technology works. And because it does, all vehicles problems can be solved. If you are having a hard time getting the results you should, you just need to go through these items and find the reasons your gains are being blocked. If you keep at it, you will find the problem and you will get the gains you are seeking.

1. Is your device making HHO?

The most common problem we encounter trying to troubleshot users' HHO Systems is that HHO is not being produced, or is not getting into the engine, for some reason. Check your system. Measure the output of your HHO cell by doing a water displacement test. A system should provide 1/4 to 1/2 liter/min of HHO per liter of engine displacement. See if you are meeting that standard. Another thing that should be checked here is whether your unit is making HHO or steam. Some of the early cell developers would run their units with so much amperage that the unit was producing more steam than anything else. If your unit runs hot to the touch, you must suspect that at least part of your output is steam. One way to test for steam is to run your gas outlet over some ice. If you get significant amounts of fog forming (water droplets), you know that at least part of your output is steam.

2. Is the HHO getting into the engine?

We have seen cases where a leak in the system was keeping the hydrogen from getting into the engine. A split hose can cause this, or one that is not attached at all. A check valve oriented in the wrong direction can block the HHO from getting to the engine. Spray your hoses and connections with soapy water to expose any leaks in your system. Fix any that you find.

3. Do you need an Electronics Enhancer?

Chances are, you do. If you already have one, then skip down to Checklist Item #4. Most vehicles will have some form of emissions components that need to be addressed. Vehicles with carburetors and/or diesel engines do not require an enhancer. Almost all fuel-injected engines will need to have its electronics handled to get the gains of an HHO System installation. You general only need to treat the Oxygen Sensors, since they are the base component within an emissions system. However, if your vehicle has a MAP (Manifold Absolute Pressure) sensor, you may very well be able to get away with just dealing with that. The Electronics Enhancer devices we offer, that deal with the MAP sensor (DEMSE) Usually, the only sensors that require handling are the oxygen sensors that are upstream of the catalytic converter. For all inquiries regarding the following Electronics Enhancer troubleshooting steps, please contact our Support Department , and we would be more than happy to help you out. There are several different scenarios, in which to determine if your vehicle needs a device to manage particular sensors that your vehicle may be equipped with. The following brings us to which Electronics Enhancer you may need.

• 3a. Do you need a DEMSE?

  If your vehicle is equipped with a MAP sensor, then one of our DEMSE (Dual Edge MAP Sensor Enhancer) units will need to be installed, along with your HHO Generator System. The DEMSE will manage the MAP sensor reading to the ECU. You may even want to consider upgrading to an EFIE unit, to manage the O2 Sensors. Treating the O2 sensors with an EFIE has proven to be a little more effective, and should give you better results from you HHO Generator System. The only drawback might be that the EFIE is slightly more expensive than the DEMSE, as it's a more intricate piece of electronics.

• 3b. Do you need an EFIE?

  If you DO NOT have a MAP sensor, then you will need to go with one of our EFIE (Electronic Fuel Injection Enhancer) units to manage the O2 (oxygen) sensor readings to the ECU (Environmental Control Unit). You may also want to consider going with an EFIE, regardless if you have a MAP sensor equipped. You may find that, by treating the O2 Sensors directly, you will get more efficient results from your HHO Generator System. You will also want to figure out whether your vehicle is equipped with Narrowband or Wideband oxygen sensors, as that will determine which type of EFIE you need.

4. Do you already have an Electronics Enhancer installed?

If you already have a form of electronics enhancement installed on your vehicle, you may want to make sure that everything is hooked up correctly. Please refer to any reference or installation manual that you may have received, for proper installation procedures. Questions in this area may always be directed to our Support Department , where we will assist you to the best of our ability.

• 4a. Do you have the right type of Enhancer?

  You may have already purchased and/or installed one of our Electronics Enhancers. There is a chance, however slight, that you may not have the correct enhancer for your vehicle. You will want to make sure that you purchased the correct device. If you haven't yet contacted us with your vehicle's information, for a System recommendation, now would be a good time. If you have a DEMSE installed, and your vehicle doesn't have a MAP sensor, then you well need an EFIE to treat the O2 sensors. If you're positive you have a MAP sensor, and you've installed the DEMSE to manage such, please refer to the manuals provided to you upon purchase. If you have an EFIE installed, and aren't quite sure why it's not working, continue to the following.

5. I'm using an EFIE, but it doesn't seem to be working?

There are two types of EFIE units to manage two types of Oxygen Sensors. Narrowband and Wideband. Of these two types, are each a version to deal with a different amount of upstream and downstream oxygen sensors that your vehicle may have. Usually, the only sensors that require handling are the oxygen sensors that are upstream of the catalytic converter. Most 4 cylinder engines will have one upstream sensor, whereas, most 6 cylinder and 8 cylinder engines will have two. There are "Dual" EFIEs that are designed to handle the one upstream oxygen sensor (along with one downstream sensor, if applicable). "Quad" EFIEs are designed to handle vehicles with two upstream sensors (and possibly one to two downstream sensors. Wideband oxygen sensors are a newer type of sensor that will not work with EFIEs made for Narrowband vehicles. Determining which sensors you have can get a little tricky, and you may want to consult the repair manual for your vehicle, or even consult a professional mechanic. You might also be able to find out from a sticker that should be located on the underside of your hood. It's a sort of mechanic's reference sticker, that notifies of some of the components. Look for "AFS" or "AFR Sensor." This will indicate that your vehicle is equipped with Wideband sensors. If you don't see that, then you most likely have Narrowband sensors. Of course, you can always e-mail our Support Department , and ask us. We will be able to look your vehicle up in our databases, and help you determine which type of sensors your vehicle has. You may even be able to find out via AutoZone's Website. Another useful tool, that we've come across, is Rock Auto; they have a vast database regarding vehicle components.

• 5a. Is your EFIE functioning correctly?

  This is rather easily tested. For all analog narrow band EFIEs, measure the voltage between the sensor wire and the ECU wire (from the input to the output of the EFIE). You should see the voltage that the EFIE is adding. It should read .25 volts, for instance, if that's what you set it for. For the digital EFIE, you can read the EFIE's output vs ground. You should see it changing between .2 and .8 volts rather rapidly, although your meter may not show the actual voltage but round them out. Also the green lights should be blinking. If you don't see this, you are either on the wrong wire or the EFIE is malfunctioning. For the wide band EFIE you must disconnect a lead and measure the current from the output of the EFIE to ground. Your meter must be sensitive enough to measure the expected output which is from 0 - 1.5 milliamps.

• 5b. Do you have the right type of EFIE?

  A majority of the vehicles on the market today are equipped with Narrowband oxygen sensors. It's possible that you have Wideband sensors, which you would need a different type of EFIE, and vice versa. Here are a few criteria that we have found useful when determining if a vehicle's oxygen sensors are either Narrowband or Wideband.

  • All vehicles manufactured before 1997 will have Narrowband oxygen sensors.
  • Some American vehicles started using Wideband sensors in 2009 and newer models.
  • Most Japanese and German models, from about 2000 forward, use Wideband oxygen sensors.
  • Vehicles that are equipped with "AFS" or "AFR" Sensors means that they are Wideband oxygen sensors.
  • Any O2 sensor that has more than 4 wires will be a Wideband sensor.
  • However, some newer Toyota and Honda models may have a 4 wire Wideband sensor.

  It may seem a little confusing, with all those different criteria, but it may help narrow down which type you have. If at any time you are unsure as to the type of O2 sensors your vehicle has, you may want to reference your repair manual for your vehicle, or even consult a professional mechanic.

• 5c. Is your EFIE installed correctly and on the correct wire?

  Refer back to the instructions for the type of EFIE you installed. If you are using a product from another company, you can still refer to our installation instructions, which usually are a little more complete. The section for finding your signal wire is pretty extensive. It is highly recommended that you have a wiring diagram of your vehicle for locating the correct wires to use with the EFIE. Also, make sure you have the upstream sensor wire(s) connected to the correct part of the terminal block, and that they are not switched around with the downstream sensor wire(s). Refer to the picture within the instructions for correct attachment of wires to the terminal block. Installing the EFIE on the wrong wire(s) is one of the most common mistakes that we've come across.

• 5d. Are the screw terminals on the EFIE's terminal block screwed down tightly?

  Often, the reason for an EIFE not to function correctly, is that one or more of the terminal block screws were not tightened down enough. This can result in a lack of connectivity within the terminal, thus the EFIE is not able to manage the signal correctly. Many people use a jewelers screwdriver to tighten the terminal onto the wires going into the EFIE's terminal block. However, you can't really get the terminal tight enough with a screwdriver that has a 1/8" diameter handle. You may want to use a larger screwdriver that has a head small enough to turn the terminal block's screw.

6. Reset your computer.

Some computers are able to "learn" and adapt to the conditions that exist in your engine. Since you have made a major change, by adding an HHO System (and possible Electronics Enhancer), you may need to reset the computer to erase what it learned about the system when it was inefficient, and start over again with the new improvements installed. You can reset your computer by disconnecting your battery ground wire from the car, and leaving it off for 15 or 20 minutes. Then reconnecting it again. I wouldn't do this every time you make a change to the EFIE's setting. But its a good idea to do once you have installed a new system. Now, don't get your vehicle's computer confused with the OBD (On-Board Diagnostics). Disconnecting the battery, and resetting the factory computer, will not cause the OBD to signal an engine code (causing your "Check Engine" light to come on).

Before proceeding to the following steps: You should definitely make sure that all of the above steps are checked. The following are less likely to be the source of the problem, and may require some additional expense. So if you aren't planning on doing expensive vehicle maintenance, you would want to make sure that the simple items above are taken care of. Further, if the checklist steps above are out, the following steps, even though expensive, may or may not resolve the situation.

7. Is your air filter dirty?

A dirty air filter can ruin gas mileage. It causes a richer mixture by restricting air flow to the engine. You can often just blow off the air cleaner with compressed air, but severe cases require replacement. Factually, you really can't go wrong with replacement because you will certainly recoup the cost in gas mileage improvement. We recommend Baldwin air filters. This is probably the cheapest of fixes. You won't necessarily see more gains from your System, although, it might help keep your engine running cleaner and smoother.

8. Do your oxygen sensors need to be replaced?

Oxygen sensors wear out. There's no way around. Some estimate that you should replace them at around 40,000 miles. Though, you should be able to get more than that on an average. A better benchmark for oxygen sensor replacement can be placed at around 70,000 miles. You should definitely be replacing them if you have 100,000 miles or more on your oxygen sensors. If you are experiencing engine stalls or fast idle, this can be a symptom of bad oxygen sensors. If they are old, it is likely that replacing them will give you a good increase in mileage all by itself, simply for the fact that their wire continuity if fresh. We have seen a number of HHO projects completely debug by doing this step. Note, use of leaded gas at any time can cause the early demise of an oxygen sensor, so keep this in mind.

9. Is there something else mechanically wrong with your engine?

If your engine isn't working properly, adding an HHO system will not correct that. You will often find that if your engine is not working properly, just fixing it can give you a dramatic increase in mileage all by itself. If you had any kind of check engine light before starting the project, you should get this fault explored and handled. If you're not sure, reset your computer, turn off all of your HHO, Electronic Enhancers, and any other added modifications, and see if you still get a fault code. If so, get it fixed first, before adding your modifications. Sometimes fault codes don't show up as a check engine light, but can still be read by a standard reader. If you have a vehicle that was manufactured in the U.S. after 1995, you can take your car to a part house, and they will often read your codes for free, and help you get them handled.

10. Do you need to treat your downstream sensors?

In the past, and in most cases, the downstream oxygen sensors are not used in air/fuel ratio calculations. Therefore they do not need to be treated. If you are planning on treating the O2 sensors of your vehicle, then we supply EFIE units we supply should already take care of that. Since we've already covered this detail earlier in the guide, you can pretty much disregard this step, as it somewhat pertains to an older version of the EIFE that we do not carry. The newer EFIE units are designed to handle both upstream AND downstream sensors now. You may just want to double-check, though, to make sure you are using the correct EFIE for the job. In this case, that you aren't using a Dual EFIE, when a Quad EFIE is needed. However, If you received a System recommendation form us, prior to your purchase, then we will have looked this up already and assigned you the correct EFIE. But we are finding quite a few cases where that's not true anymore. Dodge/Chrysler and Honda, from about 2002 forward, have documented that they are using the rear sensors as part of their air/fuel ratio calculations. Jeeps are doing this also. We have also debugged projects by treating downstream sensors on Ford F-150s and Mercedes, even though there is no documentation that the downstream sensors are used in air/fuel ratio calculatioons. It is now a primary suspect when fuel mileage is not being achieved when the steps above are all found to be in. We've never seen wide band sensors use downstream from the cat, so narrow band EFIEs are needed. A further note is that you should not use Digital Narrow Band EFIEs on the downstream sensors. These were designed to work with the phenomena that we expect from the upstream sensor activity. You can use any analog narrow band EFIE to treat these sensors.

11. Do other sensors need adjustment?

If you are treating the Oxygen Sensors, outright with an EFIE, then you shouldn't even have to bother with any other sensor. Since the O2 sensors are the base sensor for your emissions, treating them will usually override any other sensor treatment. However, after treating the oxygen sensors, the most likely sensor that may need to be treated is the MAF (Mass Air Flow) or the MAP (Manifold Absolute Pressure) Sensor. In most vehicles you have one or the other, but not both. In some vehicles you may have both, and when you do, you'll want to treat the MAF. But, having a MAF sensor almost always means you have O2 sensors, in which case by treating those you won't have to deal with the MAF sensor. If, for any reason, you feel that the MAP sensor needs to be addressed (even after dealing with the O2 sensors), we supply a DEMSE device that manages that.

Note: You may have also read somewhere that you have to treat the IAT (Intake Air Temperature) and/or CTS (Coolant Temperature Sensor). You almost never need to treat the IAT sensor or the CTS. So start with the Oxygen sensors, and work from there. However, the IAT and CTS can be tuned, and this is covered in our Mileage Tuning page.

12. What did I miss in the steps above?

All vehicles can be solved. Some of them are a little tougher than others due to the way the ECU was programmed, but they can all be solved. The technology works. If you have gotten to this point and your vehicle is still not been solved, one of the above steps may have been missed. Finding it and correcting it will allow your results to shine through. Also, if you've come to this point, and you still can't find the problem, please e-mail our Support Department and we will try to assist you to the bet of our ability. We want you to have a successful HHO installation!