{"id":11752,"date":"2021-07-09T13:42:52","date_gmt":"2021-07-09T11:42:52","guid":{"rendered":"https:\/\/advancedfleetmanagementconsulting.com\/eng\/?p=11752"},"modified":"2021-07-09T13:42:52","modified_gmt":"2021-07-09T11:42:52","slug":"aftertreatment-systems","status":"publish","type":"post","link":"https:\/\/advancedfleetmanagementconsulting.com\/eng\/2021\/07\/09\/aftertreatment-systems\/","title":{"rendered":"Why fleets should bypass the urge to bypass aftertreatment systems"},"content":{"rendered":"

Aftertreatment systems have come a long way in 14 years. With the right training, tools, and understanding of diagnostic procedures, fleets can relieve many of their common pain points without running the risk of illegal tampering.<\/span><\/p>\n

\n

Let\u2019s be honest, there are plenty of reasons why many fleets have developed such an unfavorable view of aftertreatment systems. Most tie back to three things: inconvenience, downtime, and cost.<\/span><\/p>\n

\u201cThe need for forced regens and more frequent maintenance often frustrates drivers, inciting fleets to just disable the DPF (diesel particulate filter) regen function,\u201d said Alex Parker, chief marketing officer and executive vice president of Redline Detection, a manufacturer of diagnostic leak detection equipment. \u201cBut disabling DPF regen often leads to a clogged filter, and that often leads to a costly derating of the truck.\u201d<\/span><\/p>\n

Technicians can also grow frustrated with aftertreatment systems. \u201cMany fleet maintenance executives report a 9-times to 10-times increase in technician hours required to repair and maintain emissions systems since aftertreatment systems first came about in 2007,\u201d Parker said.<\/span><\/p>\n

Much of the aftertreatment system stigma ties back to those early years. According to Johan Agebrand, director of product marketing for Volvo Trucks North America, DPFs had a lot of metal stresses and potential cracking due to the extreme thermal expansions and contractions created from temperature differences. Additionally, for selective catalytic reduction (SCR) and urea dosing systems, there were problems with crystallization and an inability to build up heat in all duty cycles.<\/span><\/p>\n

\u201cI often remind myself that the diesel engine has had 140 years to mature,\u201d added Len Copeland, product marketing manager for Detroit Products, a manufacturer of diesel engines, e-powertrains, transmissions, axles, safety systems, and connected vehicle services. \u201cAftertreatment systems have only been around a tenth of the time and have already evolved rapidly. That said, the very first aftertreatment systems were not without some learning opportunities.\u201d<\/span><\/p>\n

In early systems, Copeland says the top three issues for many fleets were DEF (diesel exhaust fluid) dosing systems, DPF cleaning processes, and thermal management.<\/span><\/p>\n

\u201cEarly aftertreatment systems often dosed DEF pneumatically,\u201d Copeland said. \u201cThat provided excellent atomization, but a dirty air system could lead to major issues. As such, most manufacturers appear to have gone to an electromechanical system that is able to achieve almost the same atomization with significantly reduced issues.\u201d<\/span><\/p>\n

For thermal management, Copeland points to physical improvements such as exhaust insulation between the turbo outlet and aftertreatment systems inlet. There have also been software improvements such as Detroit\u2019s Auto-Elevate and Asymmetric Injection which help maintain aftertreatment system temperatures for more successful passive regens.<\/span><\/p>\n

The most recent version of Detroit\u2019s aftertreatment system was released this year to meet GHG (greenhouse gas) Phase 2 regulations. \u201cWith this update, we are able to extend DPF replacement intervals up to 640,000 miles or more while further improving the SCR to increase efficiency at lower temperatures,\u201d Copeland said. \u201cThe DOC (diesel oxidation catalyst) has also been improved to allow for lower minimum temperatures during dosing. These improvements help the system clean exhaust better at lower RPMs.\u201d<\/span><\/p>\n

Volvo\u2019s Agebrand points to other recent aftertreatment system improvements. \u201cSome major changes include the fact that the SCR catalyst actually does a catalytic conversion in an increased temperature range. Thus, more variety in load and temperature from the engine will still result in a catalytic reduction of NOx emissions,\u201d Agebrand explained.<\/span><\/p>\n

Dosing systems have also improved in both algorithms and hardware. \u201cThis enables the systems to operate in a variety of conditions and with higher efficiency,\u201d Agebrand said. \u201cMaterial production design has also facilitated more compact systems that are easier to service without reducing efficiency.\u201d<\/span><\/p>\n

The need for specialized training and tools<\/span><\/h3>\n

Despite 14 years of aftertreatment system improvements, some fleets still have a bad taste in their mouths.<\/span><\/p>\n

\u201cWhen 2007 emissions standards were released, there was little to no training for the fleet technicians on how to diagnose, service, and maintain the aftertreatment systems,\u201d said Randy Griffith, director of technical sales at Emission & Cooling Solutions (E+CS), a family-owned company with nine shops nationwide. According to Griffith, this general lack of OE training is still the case in 2021. That is why E+CS specializes in helping technicians understand basic functions and diagnostic procedures for aftertreatment systems.<\/span><\/p>\n

\u201cWe have also found that many parts are replaced when there is no need to replace based on age or hours,\u201d Griffith added. For example, a DOC should last many years, but a technician is often told to simply change it rather than find the root cause. \u201cCustomers get frustrated and decide to delete,\u201d Griffith said.<\/span><\/p>\n

Even for those fleets that have attained the proper training, more hurdles exist. One is the need for specialized equipment.<\/span><\/p>\n

\u201cThe cost of tools and equipment needed to diagnose and service these systems is a newer problem for fleets,\u201d Griffith said. \u201cSmaller fleets are particularly affected because they previously could get by without having modern scan tools and equipment.\u201d<\/span><\/p>\n

Another challenge is simply the cost of exhaust items. While exhaust used to be a minimal expense for a fleet, Griffith says it has risen to the top of the list behind fuel, oil, and tires.<\/span><\/p>\n

\u201cAftertreatment components are expensive,\u201d Griffith said. \u201cWithout knowledge of the system and the proper diagnostic equipment, a fleet can easily spend tens of thousands of dollars to fix one system. Furthermore, fleets will typically deal with an ongoing occurrence until the root cause is repaired correctly.\u201d<\/span><\/p>\n

How some fleets illegally bypass aftertreatment systems<\/span><\/h3>\n

Given all of these hurdles, some smaller fleets have gone the way of deleting (removing) entire systems from a truck. This creates both environmental and legal issues. Additionally, Griffith says there can also be some drivability issues that cannot be repaired through the typical OE dealer channel.<\/span><\/p>\n

\u201cFrom my understanding, an OE dealership will not touch a truck in which the aftertreatment systems have been tampered with,\u201d Griffith pointed out. \u201cThis leaves fleets with very little support if there is a major issue down the road.\u201d<\/span><\/p>\n

Nonetheless, some fleets make the ill-advised decision to tamper.<\/span><\/p>\n

Griffith stresses the fact that E+CS has never engaged in the removal or bypassing of an aftertreatment system. \u201cWe are in the business of cleaning and repairing aftertreatment systems as well as providing aftermarket products to keep systems intact as they were intended to be,\u201d Griffith emphasized. That said, his many years in the industry have exposed Griffith to a story or two. Plus, his knowledge of engines and aftertreatment systems allows him to see where tampering could take place.<\/span><\/p>\n

\u201cI was in a shop in early April where a customer brought in a truck with a head gasket issue,\u201d Griffith related. \u201cWhen the technician went to clean the filters, he found that the DPF had been drilled out due to contamination. According to the owner\/operator of the truck, he had no idea the truck had been deleted when he\u2019d recently purchased it.\u201d<\/span><\/p>\n

Drilling out the DPF is a common way people delete their aftertreatment systems. This is generally done with a hole saw to make large passages through the filter media so it can bypass the filtration. Generally, this will cause aftertreatment codes which will then need to be either left in the system or programed out of the system.<\/span><\/p>\n

Another bypass method Griffith has heard about is the installation of block-off plates in place of the EGR cooler. That keeps the system from recirculating the exhaust back into the engine. \u201cThis is common on early aftertreatment systems,\u201d Griffith added.<\/span><\/p>\n

Tampering is illegal and costly<\/span><\/h3>\n

Just like E+CS, Volvo does not condone any activities that seek to bypass or delete an aftertreatment system. \u201cIt is considered active tampering with an emissions system and is against the law,\u201d Agebrand stated.<\/span><\/p>\n

As Agebrand pointed out, the environmental consequences of tampering are also quite clear. \u201cNOx emissions and particulates would not be controlled from the vehicle, and the air we breathe would not be as clean,\u201d Agebrand said. \u201cWhen it comes to a person or company actually tampering with a vehicle, there are many consequences including voiding of the warranty, hefty fines from the EPA (Environmental Protection Agency) or CARB (California Air Resources Board), and possible imprisonment.\u201d<\/span><\/p>\n

Some OEs have taken steps to guard against active tampering. For instance, Agebrand says Volvo has developed several functions and algorithms in combination with hardware sensors to detect any such tampering or systems that are not working. \u201cIf any customer tries to bypass the system, for example, the truck\u2018s check engine light will activate, and the vehicle will go into a \u2018limp home\u2019 state with low speed, ultimately stopping if this is not addressed by a service technician,\u201d Agebrand explained.<\/span><\/p>\n

Detroit Products\u2019 Copeland said it\u2019s important to ask why someone would want to bypass or remove an aftertreatment system in the first place. Typical answers are a perceived reduction in performance or the desire to reduce maintenance costs and downtime. However, perception is not reality.<\/span><\/p>\n

\u201cThe aftertreatment device acts as an excellent muffler, especially when paired with a quieter down-sped engine,\u201d Copeland explained. \u201cThat often leads to the perception of low power, even though power is tested by the EPA since most emissions regulations are measured in g-hp\/hr. This means a DD15 engine with 505 horsepower is truly producing 505 horsepower, for example.\u201d<\/span><\/p>\n

With respect to maintenance costs and downtime, Copeland said parked regens and unexpected repair costs should be minimal when proper use and maintenance of a newer aftertreatment system are adhered to.<\/span><\/p>\n

\u201cThose costs are also likely to be offset by the extended service intervals of modern equipment,\u201d Copeland added. \u201cSome engine oil changes are 75,000 miles and DPF intervals extend past 600,000 miles.\u201d<\/span><\/p>\n

The bottom line is that the cost of deleting an aftertreatment system is often much more than the cost of proper preventive maintenance for the life of the truck.<\/span><\/p>\n

\u201cA standard PM is under $1,000, but a new ECM (electronic control module) to work with a deleted truck can be $4,000,\u201d E+CS\u2019s Griffith explains.<\/span><\/p>\n

Innovative solutions improve aftertreatment maintenance<\/span><\/h3>\n

Even with adequate training, service tools, and preventive maintenance measures, most fleets could still benefit from additional aftertreatment system assistance. Fortunately, there are many aftermarket solutions that can help.<\/span><\/p>\n

\u201cHere at E+CS, we have a process known as the DPFRENU process,\u201d Griffith said. \u201cThis process is used to service the DPF filters themselves and can increase the longevity of an aftertreatment service. DPFRENU can also reduce strain on the engine by decreasing backpressure and creating more soot-loading capacity.\u201d<\/span><\/p>\n

As Griffith explained, good DPF cleaning programs that focus on flow rate and capacity can help dramatically decrease the cost and downtime associated with aftertreatment issues. Since there are many different processes and types of equipment available, Griffith said it is important for a fleet to partner with a good service provider. That company can proactively maintain the fleet\u2019s aftertreatment systems, as opposed to reactively deleting or removing systems that are not functioning properly.<\/span><\/p>\n

Detroit\u2019s Copeland said fleets should simply refer to Detroit\u2019s guidelines on sourcing a remanufactured filter rather than having it cleaned by a third party.<\/span><\/p>\n

\u201cOur remanufacturing process features an extensive, proprietary, environmentally friendly washing service for DPFs,\u201d Copeland explained. \u201cThis cleaning process removes more than 95 percent of the ash residue from the DPF. Incorrectly removing the harmful ash residue in the filter can create hot spots. That can lead to a cracked DPF, downtime, and additional maintenance costs. Our process is far more effective than using a \u2018bake and blow\u2019 method.\u201d<\/span><\/p>\n

Getting to the root of upstream air leaks<\/span><\/h3>\n

Redline Detection\u2019s Parker said certain product innovations can also help diesel technicians proactively seek out air leaks, which happen to be the root cause of many DPF-related issues.<\/span><\/p>\n

Research from Redline Detection suggests that an \u201cupstream component fault\u201d is the most common cause (89 percent) of DPF failure. This can be caused by small air leaks that are often undetectable. These upstream leaks create an inconsistent air\/fuel ratio that can lead to downstream aftertreatment faults and, ultimately, DPF\/SCR failure.<\/span><\/p>\n

According to analysis from Redline Detection, the most problematic upstream component failures are:<\/span><\/p>\n