| APKhaos |
01-20-2008 01:06 PM |
An decent OBDII scanner can be very useful, and can make some faults simple to DIY. The OBD system relies on a number of 'monitors', which are actually software routines that monitor specific parameters. In most cases, a monitor will set a code, but will not set the CEL until it sees a second code in the next two or three driving sessions. If it doesn't see the second code, the first code is cleared.
The scanner will show this as a pending code fault for that monitor. You can see what's up, and in many cases identify the specific component. That's typically true for O2 sensors, where the code will tell you which of the four was involved. This makes it easy peasy to replace the offending sensor.
In other cases, the codes can be misleading. My daughter's Acura threw EGT valve codes all the time. I replace the EGT, but the codes kept coming. Turns out that there was a major mod to the EGT system required, including a new EGT valve. After a bit of research, I discovered that Acura had extended emissions system warranty on her model [1997] to 150,000 miles. The dealer applied the mod, replaced ALL ignition parts [plugs/wires/cap/EGT valve] free under the warranty AND sent me a check for the cost of the EGT valve I had bought. Now THAT's service!!!
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