26 AIR REPAIR OBDII REVIEW 2008
By Jeff Katz, Katz Automotive
It seems that every week we come across new bumps in the road
of emissions repair. The most recent discovery is how fuel affects
engine operation and emissions, which raises an interesting
question: Will the correct fuel in a properly running vehicle cause
monitor tests to be incomplete? The answer may be yes.
Our vehicle was a 2002 GMC Sonoma S-10 pick-up truck,
with a 2.2 flex-fuel engine. It had 30,000 miles, and at four years
old, it had never passed a state emissions test. The first attempt
failed an OBDII test with a P0304 (cylinder #4 misfire). It was taken
to another area shop where a bad spark plug wire was originally
diagnosed and repaired. DTCs were cleared and the truck was
returned to the owner. The MIL came back on so the truck was
taken back to the shop where it received an injector cleaning. The
P0304 returned, and was again cleared. At this point, the shop
recommended new injectors, which the customer declined. Over
the next two months, the customer tried to take the emissions test
several times and was rejected for incomplete monitor tests.
When the truck arrived at our shop, the MIL was on with a
P0304, a steady 10% misfire only at idle, and most monitors were
incomplete. We did our normal baseline and diagnostic tests and
found that injector #4 did not flow as much fuel as the other three
injectors. The customer opted for replacing all of the injectors with
reconditioned units instead of just replacing #4 with a new injector.
E-85 & OBDII: What’s Fueling an Incomplete Monitor?
The misfire and P0304 disappeared and the truck ran normally.
However, on the test drive, it would not complete any monitors.
One look at the enabling criteria in the Alldata revealed why.
One of the enabling criteria for the monitors is an alcohol
content of less than 11% for the EVAP monitor and 15% for the
other monitors. This GM flex-fuel truck had a data PID for alcohol
content at 75%. A call to the customer confirmed that he was using
E-85 fuel. He decided to drive the E-85 fuel out, put in gasoline and
bring it back to be re-checked. Five days later, the alcohol content
was still 24%. However, the O2 monitor was completed. Another
week and another tank of gas later, the alcohol content read 12%
and all of the monitors except secondary air were completed. The
truck was tested and passed.
This truck was driven for three months after the initial failure.
We don’t know if the customer was disconnecting the battery
to clear DTCs before testing or if he was rejected because of
incomplete readiness tests, even though there was a P0304 DTC.
The bad fuel injector resulted in the P0304 DTC, which probably
prevented some of the monitors from enabling. After the misfire
was repaired, the E-85 fuel prevented the monitors from running.
Once the E-85 was replaced with gasoline, enough monitors
completed to pass the test.
Jeff Katz is owner of Katz Automotive on 438 S State St. in
Elgin, IL. Phone: 847-741-7033.
The question might be floating around in your head as to whether
it is worth attending an Outreach Seminar. “Why should I give up
4+ hours and a night away from the family? Will the content of
the seminar be over my head with lots of theory? Will the seminar
keep me awake after spending the whole day fixing cars?”
Let’s look at some answers to these questions. All seminars
given through Outreach are designed to give you information
that you will be able to use the next day on an emission failure.
Seminars focus on real world fixes for real vehicles. Not the “gee
wiz” variety car that you will probably never see, but the common
failures with fixes that are seen on a daily basis.
The emphasis within all seminars is to fix the vehicle and get
the monitors set so that a “pass” appears on the next emission test.
Test equipment for most failures/repairs is common to the
industry. Scanners and DSOs are the most frequent tools used
with the individual repairs.
All presentations come with a handout that can become a
reference for you. Seminar presenters encourage discussion and
keep things moving along.
One last comment, and then a challenge.
The majority of technicians that attend an Outreach Seminar
come back for more. We see some of the same technicians
coming back for additional seminars time after time. Why not give
it a try? We promise to do our best to give you practical information
that you can use.
The key ingredients for profitable vehicle emission failure repairs are
a simple mix: Tools, Training and Information. To get a handle on
how to integrate these ingredients into your shop routine, you need
only dedicate a few hours to attend the free seminars sponsored by
Thoughts from the Trainers
the Illinois Emissions Outreach program.
Three different one-night programs are offered covering
Computer Reprogramming, OBDII Emission Repair Strategies
and CAN Communication and Readiness Monitor Issues that will
sharpen a technician’s skills in this challenging field.
The classes are designed to provide up-to-date technical
information for the service technician but will also provide insight
for service managers and owners to help them better understand
the challenges they face in repairing emission failures and the
equipment they need to invest in to make the job go smoothly.
Any shop owner or technician knows that finding time to attend
seminars is difficult in our ever increasingly busy lives but the
incentive to do so is simple, you should make more money. A shop
with better trained technicians using up-to-date tools and service
information will fix more cars, faster, and with less comebacks.
That is certainly a recipe for success in any repair shop. Let
the Outreach program help you get there. And the best part about
the time you will invest is that the seminars are free!
Don’t let this opportunity pass you by. Register for the next
seminar and start cashing in on emission repair service.
My EVAP course explores the facts surrounding the Chrysler EVAP
systems. The repairing technician will view this system from a
different vantage point involving the repair and diagnosis of these
systems. A sincere approach to diagnosis has evolved due to
detailed research in this most important area of automotive repair.
It has been proven time and time again that good solid information
is what assists us all in repairing today’s systems. This is a must
attend class. Please come join us as we explore the Chrysler EVAP
systems for the first time!
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