Re: 1999 Miata - Check Engine - Help (not resolved)

Go to one of the auto parts stores that can pull the codes for you. That 
will tell you what is causing the problem.

There is a chain of events that can happen. Bad wires can damage coil. Bad

coil can damage O2 sensor. Bad O2 sensor can damage catalytic converter.
Not 
dealing with a problem in a timely basis can be very expensive!

"Pat Dreiding" <patdreiding@[EMAIL PROTECTED]
> wrote in message 
news:ZsJuj.48460$we5.32680@[EMAIL PROTECTED]
> After replacing the plugs & wires the problem went away for about 30 
> miles.
>
> It's back.  What's my next step?
> How do I check the O2 sensor?
> Do I replace the Catalytic Converter?
>
> Where's the best place to get replacement parts (O2 sensor, Catalytic 
> Converter)?
>
> Is this something I can easily do myself?
>
> Thanks,
> - Pat
>
> "Pat Dreiding" <patdreiding@[EMAIL PROTECTED]
> wrote in message 
> news:SYMsj.343$Cs.318@[EMAIL PROTECTED]
>>I need a few words of wisdom about my '99.   It has 65K miles on it. 
>>About a week ago I did something that I believe was very stupid.   I 
>>cleaned my engine by hosing it down.  The car ran ok for a little while,

>>but then stopped.  The engine light was on. Yes - you guessed it.  Water

>>in the plug wells.  Ugh!  I spend the time to remove the water and dry
the 
>>wires & plug wells.  The car was running fine for another few days 
>>afterwards and then the check engine light returned.  The autozone tech 
>>told me the trouble shooting error code is P0420., which is:  "Catalyst 
>>efficiency low-bank - the oxygen sensors monitor the catalytic
converters 
>>ability to store oxygen.
>> Possible causes are:
>> 1. Catalytic converter defective (Failure possibly due to #2, 3, or 4);
>> 2. Engine msfire or running condition;
>> 3. Large vacuum leak;
>> 4.  Engine oil leakage into exhaust-value guide seals, piston rings
>>
>> Any suggestions on approach to uderstanding and fixing the problem?
>>
>> I've been considering replacing the plugs & wires.  Is this the correct

>> first step?
>>
>> Thanks,
>> - Pat
>