The public’s lack of knowledge about automotive repair can lend itself to
being the source of particle humor for some of those who are knowledgeable of
cars. I will never forget the customer that came into the shop and asked for an
estimate to replace the bearings in her muffler and the halogen fluid in her
headlights. The young lady became irritated when we informed her there were no
such things as muffler bearings or halogen fluid. She was adamant we give her a
price because her husband told her that was what needed to be replaced. After a
few minutes of explaining, the young lady final understood she was the victim of
her husband’s practical joke. Muffler bearings and halogen fluid are fictional
repairs. However, a new fluid which few are familiar with is Exhaust Fluid. Yes,
there really is a thing as exhaust fluid.

Diesel Exhaust Fluid (DEF) is an aqueous urea solution used in Selective
Catalytic Reduction (SCR) systems to lower nitrate oxide concentrations in
exhaust emissions from diesel engines. Have you ever seen a diesel vehicle
blowing black smoke from its tailpipe? That black smoke is diesel particulate,
soot, that’s polluting our atmosphere. Exhaust fluid was created as a solution
to reduce diesel particulate emissions (soot) by cleaning the Diesel Particulate
Filter (DPF) from time to time. Now you ask, “What’s a Diesel Particulate
Filter?” Yes, there really is a thing as a DPF Filter.

In December 2008, the State of California passed legislation requiring all
roadgoing diesel trucks and buses in California be retrofitted, repowered, or
replaced to reduce particulate matter (PM) emissions by at least 85%. Most auto
manufacturers responded by proactively installing filters into the exhaust
systems of most of their new diesel trucks to catch the diesel particulates. The
filter looks like a huge canister in the exhaust system with small tubes leading
into it. The small tubes occasionally inject the exhaust fluid into the
particulate filter to clean it of all the captured soot. This filtration system
is real and is vital in helping keep our air clean. Thank you California!

Blinker fluid, halogen fluid, changing the old air in your tires and muffler
bearings are all common practical jokes pulled on the unsuspecting. However,
don’t be so quick to curse your auto technician if he recommends you replace a
part you have never heard of before. Automotive technology changes from
year-to-year and new parts are constantly being added.