O2 Sensor?
in [Toyota]
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From: Mark A on 14 Dec 2008 11:04 "Sarah Houston" <SHoust(a)pndfnospam.com> wrote in message news:Xns9B741054FA82ASntzldfrdSntzldfrdco(a)216.196.97.142... > Well the MPG hasn't been so great this past year or so. If you are going to keep your car for awhile, go ahead and replace the O2 sensor(s) if you suspect it is bad. It is likely that it will eventually go bad anyway. I had my front break pads replaced even though there was probably another 10,000 miles on them, because my car was in the shop for something else and my time was too valuable to worry about having to replace the pads later. Regarding the recommendation from Bosch, remember that on new cars the tune-up interval is 100,000 miles (mainly because the only thing in a tune-up these days is replacing the platinum spark plugs). Also remember that they are in business to make money, and the more Bosch products you buy, the more money they make.
From: Jeff Strickland on 14 Dec 2008 12:23 "Sarah Houston" <SHoust(a)pndfnospam.com> wrote in message news:Xns9B73C8AABB540SntzldfrdSntzldfrdco(a)216.196.97.142... >( 93 Corolla 1.8L 7AFE ) > > I had no idea about this but Bosch suggests replacing the oxygen sensor > with every tuneup? Huh? Mine has never been replaced as far as I know. ( > we got the car at 45k miles, it now has 172k ) > > http://www.boschautoparts.com/Products/OxygenSensors/ > > Seriously? > > I priced a Bosch one at about $60 with tax. > > Is there any real advantage to using a Toyota part on this? > ( outside of to Toyota, because it costs more? ) > My guess is that Bosch is interested in selling parts. I would not hesitate to install a Bosch O2 Sensor when the engine calls for one (by causing the Check light to come on). I do not see a need to replace one simply because time or miles have passed.
From: Ray O on 14 Dec 2008 13:31 "Sarah Houston" <SHoust(a)pndfnospam.com> wrote in message news:Xns9B741054FA82ASntzldfrdSntzldfrdco(a)216.196.97.142... <snipped>> > > Well the MPG hasn't been so great this past year or so. > Keep in mind that on a 5 year old vehicle operated where salt is used on roads, the O2 sensor may be rusted in place. Hopefully, this won't be the case, but be prepared to replace the exhaust manifold as well (probably an extra $300 or so) if it strips when removing the old sensor. In my 35 years (some of it spent fixing cars that dealers couldn't fix) or so working on cars, I have become a big believer in the adage, "if it ain't broke, don't fix it." You may get 1 or 2 MPG better fuel economy with a new sensor. People claim bigger improvements, but I doubt if your fuel economy will improve more than that. There is also the possibility that your sensor is fine and you will see no measurable improvement in fuel economy. You can do the math on whether or not replacing the O2 sensor might be cost effective. Here is an example: 10,000 miles driven per year divided by your current MPG (25 in this example) = 400 gallons of fuel 400 gallons of fuel times an average fuel price of $.50 = $600 in fuel. 10,000 miles divided by (the improved 26 MPG) = 384.6 gallons of fuel 384.6 X $1.50 = $577 in fuel, or a $23 improvement over 10,000 miles. 10,000mi. divided by 27 MPG = 370 gallons 370 X $1.5 = $555 in fuel, or a $45 improvement. Assuming that you do not need to spend additional money to replace the exhaust manifold and that the cost of a replacement O2 sensor is $60 with no labor and you already have the tools to do the job, a $23 improvement will take a little under 3 years at 10,000 miles per year to break event, and a $45 improvement will take about a year and a half to break even. Obviously, there are a lot of variables in this equation. More miles driven and higher fuel costs will speed up the break even, and higher replacement costs like a stripped manifold, including labor charges, or lost productivity while the vehicle is not usable will slow down or even eliminate any savings. Unless something is actually malfunctioning, there usually is not one trick or fix that will make a dramatic improvement in fuel economy. There are a lot of other things you can do that can add up to improved fuel economy, and a lot of them cost nothing to implement or are part of routine maintenance that is recommended by the folks who designed your car. This is an apples and oranges comparison, but my car with a 4.3 liter V8 gets 18 city/26 hwy in the winter, 19/27 in the summer with the original O2 sensor. The 4.3 liter is roughly 2.3 times the displacement of the 1.8 liter in a Corolla but I doubt if the Corolla gets 2.3 times the fuel economy. I', cheap so I only use the tricks that cost me nothing to improve fuel economy. -- Ray O (correct punctuation to reply)
From: larry moe 'n curly on 14 Dec 2008 15:37 Sarah Houston wrote: > After doing some extensive reading, it began to come clear how the O2 > Sensor performance could be off, yet not be able to see any symptoms > (other than lower gas mileage) with the tools I was using. It turns out > that the O2 swing cycle shown in the photographs is the swing time of > the overall system and not just the O2 sensor itself. To really examine > the performance the O2 sensor, for example to determine if it was > developing a lean or rich offset, one would have to use a digital volt > meter with an averaging feature connected directly to the sensor and > look for the 450mV centerline signal in a known, properly performing > system centered at the 50% duty cycle. Are there digital voltage meters that don't average semi-fast signals? I think for testing O2 sensors, a meter with a fast-reacting bar graph would be better. > To measure responsiveness, one would have to use a laboratory scope Why? It's just a low frequency signal that any regular scope, or even a cheapo handheld 1 MHz scope/DVM can display. Do any owner's manuals mention a replacement interval for the O2 sensors, that is, for vehicles made since the mid-1980s?
From: Sarah Houston on 14 Dec 2008 17:56
"Mark A" <someone(a)someone.com> wrote : > "Sarah Houston" <SHoust(a)pndfnospam.com> wrote in message > news:Xns9B741054FA82ASntzldfrdSntzldfrdco(a)216.196.97.142... >> Well the MPG hasn't been so great this past year or so. > > If you are going to keep your car for awhile, go ahead and replace > the O2 sensor(s) if you suspect it is bad. It is likely that it will > eventually go bad anyway. I had my front break pads replaced even > though there was probably another 10,000 miles on them, because my > car was in the shop for something else and my time was too valuable > to worry about having to replace the pads later. > > Regarding the recommendation from Bosch, remember that on new cars > the tune-up interval is 100,000 miles (mainly because the only thing > in a tune-up these days is replacing the platinum spark plugs). Also > remember that they are in business to make money, and the more Bosch > products you buy, the more money they make. Yes, I understand that. :) |