I am starting this post to help summarize with a FAQ what’s been discussed in the long “VCM - A better way to disable.” thread. It has become very long and so I realize it’s hard for newcomers to weed through the entire thread to find the information they’re looking for. I would suggest that you please post your questions / comments not addressed here to the other thread in order to keep this thread short. If any of you have additions to this, please PM me and I’ll revise. I would humbly suggest to the moderators that this thread be made a sticky and then closed off after a short revision period.
Q. What is the VCMuzzler II and what does it do?
A. It is a device that plugs in line with your Engine Coolant Temperature sensor (ECT1) to effectively lower the perceived temperature reported to the ECU. The goal is to lower the temperature just slightly so that the ECU thinks the temperature of the engine is just below full operating temperature, hence disabling VCM from engaging.
Q. What is the difference between the VCMuzzler and the VCMuzzler II?
A. The original version had one hardwired resistor. It became apparent early on that due to the variability between vehicle cooling system components, one resistor fits all was not sufficient. The VCMuzzler II comes with the ability to switch resistors easily. The original version is discontinued.
Q. Why would I want to disable VCM?
A. There are many discussions on this on many forums. VCM (Variable Cylinder Management) is a feature on Honda and Acura vehicles whereby cylinders are deactivated during light load cruising conditions in order to increase fuel economy numbers. However, it can lead to problems including but not limited to: excessive oil consumption; spark plug fouling; misfires and misfire codes; worn engine mounts; vibrations during VCM activation; hesitation when accelerating out of VCM mode; sense of a lack of power when cruising. Honda has admitted to some of these issues with the loss of their class action lawsuit, warranty extensions and TSB’s. GM has similar issues with their ACM technology.
Q. How hard is it to install?
A. Most people can install it in less than 5 minutes. It is plug and play.
Q. Does the VCMuzzler II come with instructions?
A. Yes, it comes with a 5 page color illustrated manual.
Q. If Honda is aware of the issues, why would they not discontinue it or offer an option to turn it off?
A. With VCM technology in it’s V6 vehicles, Honda benefits from an EPA / CAFÉ regulations rating. Should Honda remove it or offer the driver an option to disable it, they would lose this rating and be subject to penalties for not meeting the regulations.
Q. Which vehicles does the VCMuzzler II work on?
A. The following vehicles that are equipped with VCM.
Accord & Accord Hybrid 2005+
Q. Does the VCMuzzler II change the operating temperature of my vehicle?
A. No, your vehicle’s cooling system is unaffected. The fans operate as usual as they are turned on by ECT2. The actual operating temperature of your vehicle is unchanged.
Q. What can I expect to happen after installing the VCMuzzler II?
A. Your temperature gauge at full operating temperature will read just slightly lower. Your ECO light on your dash board should not come on during normal driving and VCM will not engage. In extended idling conditions i.e. traffic jams, the engine temperature may creep up to slightly above the VCM threshold, resulting in seeing the ECO light for about 30 seconds when resuming driving. After this, the ECO light will go out and VCM will be deactivated again.
Q. Will I still be able to know if my engine overheats?
A. Yes. Your temperature gauge reads only slightly lower. Monitor your engine temperature (as you always should) and if you see an abnormal rise well above this new lower reading, then your engine may be overheating. You will still get an overheat warning on your dash if your engine overheats.
Q. Are there other systems that will be affected by using the VCMuzzler II?
A. There have been no reported detriments to using the VCMuzzler II. The idle speed, Air/fuel ratios, timing, shift points etc. are all unaffected. This is due to the fact that the perceived engine temperature is only slightly decreased and the engine is well out of cold startup mode. The engine and transmission operate as if the vehicle was at full operating temperature. Because VCM involves the deactivation of cylinders, the ECU ensures the engine is COMPLETELY hot before deactivating cylinders to ensure the oil is up to temperature and the cylinders are being lubricated properly. Deactivating a cold cylinder would mean excessive engine wear and uneven temperatures across the engine, resulting in improper piston clearances / ovality etc. This is why VCM can be deactivated with this slight temperature drop without affecting other systems.
Q. I’m experiencing vibrations while driving. Will the VCMuzzler II eliminate them?
A. If the vibrations occur only when the ECO light is on during cruising conditions, then it’s very likely that the VCMuzzler II will eliminate them. Vibrations can occur for many other reasons, including wheel out of balance, wheel bearings, warped brake rotors, worn engine mounts etc. The VCMuzzler II will not eliminate vibrations from other sources.
Q. My vehicle has excessive oil consumption and / or misfires. Will the VCMuzzler II solve these issues?
A. It’s hard to say for sure. A great many people have reported either no more oil consumption or a reduction in the amount consumed. Some have reported no more misfires. There are some that report no change to either. It all depends how far gone your vehicle is with regards to these issues. Excessive oil consumption is a result of improper loading of the oil ring on your piston and eventually it will plug off and no longer work as it should to effectively wipe oil from your cylinder walls. If it isn’t in too bad of a condition, using the VCMuzzler II to fire the cylinder all of the time may reverse this and lead to a decrease or elimination of oil consumption. If the oil ring is too far gone, the damage can’t be reversed. The same is true for plug fouling / misfires. There’s no way to predict an improvement or not, but many have reported improvements or a complete absence of any further problems.
Q. Have there been any bad consequences reported from using the VCMuzzler II.
A. No, the response has been overwhelmingly positive with no detrimental effects reported. Just about every user reports an increase in driving enjoyment due to having 6 cylinder power all the time with reduced hesitations. Most, if not all of the reported issues revolve around the resistor selection, which are easily resolved.
Q. What will happen to my gas mileage?
A. Most have reported only a slight drop of 1 mpg. Some report either no change or an improvement. The improvement may be because of a change in driving habits as some, including myself, would tend to unconsciously accelerate more than necessary to kick out of ECO mode when approaching hills or other conditions where more power was needed during cruising conditions. At any rate, the slight drop of 1 mpg is acceptable to most. There have been no reports of more than this.
Q. Do I have to remove the VCMuzzler II before I take my vehicle in for service or an emissions inspection?
A. If the vehicle is under warranty, I would recommend removing it. There’s no practical reason why Honda would void your warranty for using the device, but any modification to the vehicle can be used as attempted grounds to void the warranty by some unscrupulous dealers. I have not heard of any cases of this to date. Everyone so far that has left it in for a service trip has reported either it was not even noticed (as it looks OEM) or in a few cases, the service people have actually recognized it for what it is (I guess word is getting around). In none of these cases have they said that it’s a bad thing and should be removed. In a couple cases, the service person endorsed it, saying it’s a good thing, others will not endorse it (presumably because it’s not OEM) but do not downplay it either. I have sold some to dealerships and repair shops.
For emissions inspections, again, some report leaving them on and passing with no problem. The self-diagnostics all pass with the VCMuzzler II installed. There have been no reports of failing an inspection because the VCMuzzler II is installed.
Q. Why are there two resistor connectors supplied with the VCMuzzler II? Why are there other optional resistors and do I need them?
A. The VCMuzzler II ships with an 82 ohm (blue) and a 120 ohm (red) resistor. The different resistors are to account for variances between vehicles cooling system components such as thermostats, sensors, cooling system fluid and condition and radiator condition as these variances can result in slightly different operating temperatures. Climate can play a role in selection as well. You really can't tell what you need until you try it. Always start with the 82 and if necessary move up to the 120. On rare occasions, resistors above or below this range (150 ohm white or 68 ohm yellow) are needed . Additionally, there's an intermediate 100 ohm (orange) resistor that, again, is required in a low percentage of vehicles. Only the red and blue resistors that are used in the vast majority of vehicles are included as standard since supplying all resistors as standard would drive up the cost unnecessarily for most people. Optional resistors can be purchased at the same time as the VCMuzzler II if desired, or can be purchased separately later if needed.
Q. How do I decide which resistor to use?
A. Start with the blue resistor that comes installed with the VCMuzzler II. Test drive with this for at least a week and monitor how often the ECO light comes on. If it comes on too often during normal driving (not just occasionally after extended idling), then you should switch to the red resistor and again monitor for a week.
Sequence for resistor selection should be:
After each change in resistance, monitor for one week.
Result: ECO light off always or vast majority of the time – no change needed
Result: ECO light still coming on frequently under normal driving conditions – Increase resistance
Result: CEL comes on and does not go away after one week – Decrease resistance
In the rare cases where the optimal result can’t be obtained with the standard red or blue resistor, then an optional resistor will be necessary.
Q. How do I know if I’m using too high of a resistor?
A. If you get a Check Engine Light (CEL) warning on your dash that says “Check Emission System” and the code returned is “P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)”. If you don’t have a code reader, you can go to your local parts store and they will read and tell you the code for free. If you see this CEL right after installing the VCMuzzler II or increasing the resistance, then this is almost certainly the error code you will get. This code is generated when the ECU perceives the engine temperature to be outside of the acceptable range of the thermostat (which is usually pretty generous).
Q. I got a CEL on my dash after installing the VCMuzzler II or switching resistors…What should I do?
A. First of all don’t panic. The CEL can be triggered for two reasons. Firstly, you may have installed it when the engine was not completely cold. It should always be installed or resistors should be changed first thing in the morning before the vehicle has been started. The second reason may be that the resistance is too high for your vehicle.
If the CEL was a result of it being installed while the engine was too warm, the CEL should clear on it’s own after a few drives or it may take a few days.
If the CEL was a result of too much resistance, it either will not clear on its own after a week, or it will clear and then return. In this case, the resistance will need to be decreased… see the above two FAQ’s.
If you wish to clear your CEL manually, disconnect the battery for 20 minutes.
Q. I’ve been using the VCMuzzler II for a while now and all of a sudden I got a CEL. What happened?
A. It could be your cooling system has changed slightly and you have the P0128 error. It may also be that the ambient temperature has dropped due to the seasons and this has affected your operating temperature. However, it might be another error completely unrelated to the VCMuzzler II. You should read the code if you have a reader or get it read for you for free at an auto parts store. If it is the P0128 code, it may just have been an anomaly and it may clear again on its own after a while. If it doesn’t, you may have to change to a lower resistance. If it is a different code than P0128, then you’ll have to address whatever the code is telling you.
Q. What is the cost? Why is it so expensive? Why is it so inexpensive? How do I order?
A. The cost is based on many things, supplier costs, ebay and / or paypal fees increasing and on the time it takes to manufacture as I make each one by hand, not with high volume manufacturing equipment. I adjust the cost occasionally due to increasing costs. Some wonder why I don’t charge more. If you’re interested in purchasing and wish to know the cost, send me a PM. If you know you want to purchase, send me your name, shipping address, paypal email address and the year and model of your vehicle. I’ll send you a paypal invoice and once paid, I can ship it out along with the instruction manual.
Q. How long does it take to ship? How long does it take to arrive?
A. I usually ship next business day, sometimes it can be up to two or three days at the most. Delivery time from ship date to the US is on average 2 weeks, but can take up to three or more occasionally. The main delay is always in US Customs as they are being shipped from Canada. US customs processing times are very erratic. Shipments within Canada take 3-4 business days.
Q. I have not received my VCMuzzler II yet and it’s been a long time. What can be done?
A. I can’t initiate a claim until 30 days past the ship date. Once 30 days has passed, I can initiate a claim and send out another. This has only been necessary in a few cases.
Q. A wire or resistor has pulled out of the connector terminal. What should I do?
A. You cannot repair it once this has happened. To prevent this, never pull on the wires or the resistors, only pull on the connectors themselves and take care not to put tension on other wires when doing so. If this does happen, PM or email me to arrange a repair.
Q. How long will the resistors last?
A. It will likely outlast you and your vehicle. The resistors are much higher rated than necessary and not taxed very hard at all.