[Jim]

I have had the Ugly fix for three years and did not notice any changes good or bad. The assumption was that it only works on some of the engines. A computer diagnostic was done and did not prove the high altitude sensor was tricked in disabling the EGR as designed. I have the 12.7 liter S60 not the 14 liter.

[glen]

The principle behind the Ugly Fix is simple. It tricks the ECM into believing the coach is at an altitude greater than 11,000 above sea level. Detroit Diesel evidently determined too much power is lost by an engine above that altitude so the ECM disables the EGR function at or above 11,000.

When the EGR is functioning it is supposed to lower internal cylinder temps to reduce NOX. To accomplish that it sends exhaust gas back into the engine. But when it does that the engine loses power, so simultaneous with sending exhaust gas into the engine, it also sends more fuel and increases turbo boost to offset the power loss. We cannot see it on our turbo boost gauge, but boost is increased from 30 PSI to 50 PSI. At high altitude a turbo has a difficult time supplying needed oxygen to the engine so that is why on some coaches the default is to disable EGR functions over 11,000.

But if the programming of the ECM is such the EGR is not disabled above 11,000 the Ugly Fix will not work. That change can be programmed is a Detroit dealer can be convinced you do a lot of driving at high altitude and you believe the EGR is killing your power when driving at high altitudes. Add to the story that at high altitudes you see black smoke coming from the coach. Don’t let the Detroit dealer replace the turbo or associated parts, just have him check the program and change the default setting so the EGR is disabled above 11,000.

Then go down the street, open the RH side door at the engine, reach in and add the ugly fix.

I was at 5.9 MPG based on over 20,000 miles of driving. The Ugly Fix (EGR disable) changed that slowly over about 2 years to consistently over 6.5 MPG. My driving speed and habits were consistent so the only reason I can think for the improvement is the EGR disable. It is illegal. But it eliminates pouring dirty exhaust gas into an engine along with increased fuel flow. Anecdotal evidence has suggested the EGR is contributing to engine issues over the long term specifically to the #6 cylinder.

[Art]

Thank you Jon!

[Archived]

Jeff, you don’t say where you live, but if you have a Detroit dealer willing to work with you they might be willing to check your default setting for EGR operation. They might even be allowed to change it if necessary to cut out at 11,000 so the Ugly fix will work.

If they are really willing to help you they can change the EGR cut in parameters beyond the altitude setting. They can program the EGR cut in to be 3200 and cut out to be 3400 effectively permanently disabling it without the Ugly Fix.

But that is illegal. And the consequences if caught are severe.

It becomes a question of how important disabling the EGR is to you. You will get improved mileage because you are not dumping excess fuel into the engine to compensate for when it dumps exhaust gas into the engine. But I can say for sure the improvement in mileage is only going to be 10% or so. If your fuel consumption is the driving force and you want to improve it, slow down. That will be a greater savings. I drive at and have consistently driven at 62 MPH. If you drive faster you pay for the speed in fuel consumption.

[Archived]

I heard from an un-named source that we, I mean them, had good results from installing the fix. We, I mean them, noticed a significant reduction in the soot deposited near the exhaust and on the front corner of the toad.

This is after about 5,000 miles. I can’t believe that visible soot reduction is anything but good. Not putting that stuff in the cylinder has to be good.

I’m just saying this for a friend…

[Archived]

Thank you very much for the additional information, Jon.

I am interested in the Ugly Fix primarily to have a cleaner and more dependable engine. Any increase in fuel mileage would be nice, but like you, I prefer to set the cruise at about 63 / just below 1500 RPMs as it seems to make driving so much more relaxing and enjoyable – no fighting traffic.

We are on our maiden voyage of this, our first bus, currently in Pennsylvania headed to Maine, yet if you know of someone who might help, we would stop by on the way back down 🙂

Please feel free to email me if preferred. THANK YOU AGAIN and definitely appreciate all your detailed writings! I have read them all and try to figure things out before asking for help. I look forward to the day when I, too, can contribute.

[Archived]

Les – THANK YOU! Glad to hear those folks had good results 🙂

[Archived]

We of course are all talking hypothetically here so I will echo what Les reported.

If the EGR fails to function and exhaust gases aren’t being shoved into the engine intake manifold I believe several things are going to happen, hypothetically speaking of course. First the engine is only being made to run on clean fresh air and fuel. No exhaust gases are being introduced so that means no additional fuel is pumped into the engine to compensate.

As a result fuel mileage can be expected to increase and it does. The savings in fuel cost might not appear significant, but for the average refueling the savings will pay for a meal at Olive Garden or Cracker Barrel.

Or said another way, you get to spend 10% less time at truck stops.

But for those who pay attention to their oil there will be a very noticeable change, hypothetically speaking of course. Instead of the oil color changing to black within 50 or 100 miles after an oil change, it will remain a golden color for 2500 miles. It may require a few oil changes before that impact is seen, but once the exhaust particulate is cleaned from the engine it is truly amazing how clean and for how long the oil is a nice golden color.

I recently replaced my oil pan gasket and when I dropped the pan I expected to see some sludge or collected material in the bottom of the oil pan. NADA. Nothing. Nil. Absolutely clean. That was a huge surprise and there is no doubt in my mind the 5000 mile oil changes are the principle factor, but the fact no exhaust is run through the engine has to be a major contributor to the fact the engine is clean inside.

Maybe some day environmentalists can take the time to explain to me how burning a lot more fuel is somehow better for the environment, which is what EGR does.

[George]

Just Joined and already I am loving this place. Thank you for the information.

C&T