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MORE: Engine sensor questions
Engine Sensors - Computer Sensors - ECM
Sensors Questions - This
category contains featured questions as
examples. They relate to most vehicles.Question:
1998 Mitsubishi Mirage mileage:
90,000. I am replacing the exhaust manifold. Old
manifold has a some sort of sensor screwed into it, but
the new one does not have a port for the sensor. Can the
car function adequately without the sensor? What is the
sensor?
Answer: The sensor you are
referring to on the exhaust manifold is the oxygen
sensor. It is an extremely important part of the
computer management system for your engine.
Question: 1996 Mazda 626 mileage:
70,000. What are all the problems that a failed oxygen
sensor causes if I keep driving my Mazda 626 (96)? Will
my car quit on me or anything? What am I in danger of as
far as hurting my car? I just need to get paid to have
the money for 2 oxygen sensors.
Answer: Oxygen sensors read
the fuel mixture in the exhaust and send the information
to the computer. The computer then, adjusts the fuel
mixture. By not replacing faulty oxygen sensors, your
can expect that your check engine light will come on
accompanied by erratic idle and poor running and fuel
mileage. Your exhaust system could sustain damage by
driving it with faulty oxygen sensors. They should be
replaced as soon as possible.
Question: 1999 Ford Escort
mileage: 86,500. Garage suggested several possible
problems starting with Oxygen sensor - cost of repair
$200. My problem is that he does not know if this is the
problem, and that I will have to keep on paying for
every fault finding repair even if that's not the one!
Can you help with diagnosis and the best way forward?
PLEASE.
Answer: It is possible that
the oxygen sensor is faulty. The sure fire way of
finding out is to scan the computer for fault codes
which will pinpoint the malfunctioning component.
Question: 1998 GMC Sierra mileage:
70,000. The service manual for my GMC Sierra tells me
that my truck has 4 oxygen sensors. They are designated:
Bank 1 Sensor 1, Bank 1 Sensor 2, Bank 1 Sensor 3, and,
Bank 2 Sensor 1. The manual does not clearly indicate
the location of each of these sensors. A GMC technician
tells me that the term "Bank" refers to a particular
side of the engine - Bank 1 refers to the side with
cylinder number 1...the driver's side (as the plug wires
are numbered 1,3,5,7). You'd think it would be easy to
deduce the placement of each oxygen sensor. Here's the
problem: Only one oxygen sensor lies beneath Bank 1. The
other three are under Bank 2... two in front and one
behind the catalytic converter. My information seems to
be contradictory. Error code P0153 tells me I need to
replace Bank 2 Sensor 1. Can you verify its location?
Thanks.
Answer: The first oxygen
sensors down the exhaust pipe are the primary sensors
(1) the sensors after the exhaust is sensor secondary
(2) bank one is the side with number 1 cylinder (drivers
side)
Question:
2002 Dodge RAM 1500 mileage: 85,000. Would a bad
oxygen sensor (upstream) cause a truck to hesitate
during acceleration in low gears? What causes these to
go bad?
Answer: It is not likely for an
oxygen sensor to cause the poor running
you are experiencing. It sounds more like a
clogged fuel filter or a failing fuel pump. Oxygen
sensors eventually burn themselves out due to the heat
of the exhaust.
Question:
1999 Toyota Tercel 4 cyl mileage: 91,000. Dear Bob
and Ken: My problem concerns my Toyota Tercel,
91000 miles, 4-speed manual transmission, most recent
oil change was about 1800 miles ago, and no major
repairs since purchasing the car at 40000 miles.
I recently made a 1600-mile trip from Virginia to
Colorado; I had the oil changed, fluids topped-off, and
air filter replaced. Additionally, I had an
emissions inspection done a few weeks before, and the
results were excellent. Approximately half way
through the trip and some very bumpy interstate driving
in Arkansas and Oklahoma, my "Engine" light came on.
I pulled over immediately to check under the engine,
checked the oil level, belts, hoses, etc. and found no
noticeable irregularities, except that the overflow
container for the radiator fluid was empty. There
was still plenty of fluid in the radiator itself, but I
replaced the fluid/water mixture anyway. I noticed
no odd smells or drivability difficulties, so I
continued driving. I stopped overnight and the
following morning, I checked my owner’s manual and it
said that this light comes on due to a problem with the
engine's electrical system. Being that the roads
were rough, I suspected maybe a fuse had been knocked
out, so I removed, inspected, then replaced all of the
fuses. I started the car and the engine light was
off. I continued driving, but after about 6 hours
of interstate driving (70-80 mph) the light came on
again. Still, I did not notice any smells,
sounds, or drivability problems. I continued to
drive as I was in the middle of nowhere and arrived in
Colorado, still with the engine light on. I spoke
with a technician about this before and his
recommendation was that the oxygen sensor could be the
problem. I have researched the function and
possible problems of the O2 sensor and it seems like if
that were the culprit, my exhaust would smell like
"rotten eggs" OR produce a black smoke (depending on
lean or rich mixture). Is this correct? Or
could the sensor be malfunctioning WITHOUT a real
problem with the mixture? What type of problems
could develop with continued driving? Could there
be another cause to the engine light coming on?
Is there some way to check the sensor myself without
having to take to a mechanic? Could the missing
radiator fluid have caused something to go wrong (I have
noticed no leaks in the overflow tank since)?
Could the change in altitude cause something? I
apologize for the length of this, but wanted to make
sure to get all of the information here. Thank you
in advance for your help!
Answer: You probably do have a faulty
oxygen sensor. Replace with new to recheck system.
If your problem persists, then scan the computer for
fault codes. Oxygen sensors go out of range
at times, but still work.
MORE: Engine sensor questions
Repair Topics / Engine
Sensors-1 / Engine
Sensors-2
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