Disconnecting the battery for a while will work, except that it won't fix
whatever caused the CEL to turn on in the first place, and you will soon see
it again. Do yourself a favor and have it properly diagnosed.
AutoZone stores offer free on board diagnostic checks. They can read the
code that caused the light to come on in the first place, and reset it.
They may not reset if if you are due to have an emissions test in the near
term ( they will ask you about this). You want to know what caused the
check engine light (CEL) to come on in the first place. Depending on the
code, its very likely that it will come right back again after clearing, and
will continue to do so until the problem it is trying to alert you about is
In my experience, there are very few "spurious" codes that will NEVER come
back after a reset, other than a misfire code from driving through a huge
puddle that wets down the spark plug wires!
AZ also sells a reasonably priced line of on board diagnostic Type II (OBD
II) code readers that you can use to read and reset the trouble codes
yourself at an interface plug located under the dash near the steering
column. All makes of 1996 and later USA market passenger vehicles use this
standard diagnostic code system, so you can use the reader on any such
vehicle. You can recover the reader cost pretty quickly by charging all
your friends who want to "borrow" it a few bucks each once they find out you
In a 97 Ford product, some of the most likely codes you will see are P0420
and P0430, which indicate that your cat converter is wearing out. If those
codes show, your driveabilty will not likely be affected, but will have to
be dealt with prior to your next emissions inspection. Most states now use
the information read at the OBDII interface as a the basis for pass/fail
emissions testing on cars having that diagnostic system. If you have a CEL,
you will fail. And the system is smart enough to flag if someone cleared
the CEL with a reader within a certain number of driving cycles. That flag
will not clear until all on board diagnostic tests pass on their own for
several test cycles in a row after the reset, and if present during a state
emissions test, will also be the basis for a failed test.
Bottom line - the CEL s trying to tell you something - pay attention to it!
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