1999 Miata - Check Engine - Help

That is what I would do. The plug wires are probably due for replacement even if they are not the problem. It is likely to take care of the problem and is fairly inexpensive and easy to do.

How does the car drive? Bad plug wires will cause hesitation on take-off. A bad catalytic converter will probably cause you to suffer a loss of power that is constant and it may get worse with increased exhaust flow.

If it is problems #3 or #4, then it is probably not related to the engine wash, unless you possibly sprayed a vacuum hose loose.

Good luck!

The other Pat

Hi Pat, I'd suggest that after a drowning, that the most likely fault is the misfire (of course). If it was me, I'd be spending time checking and drying ignition components yet again before spending cash. Don't know the '99 model but under the distributor cap in most cars is a good place to start.

OzOne of the three twins

I welcome you to Crackerbox Palace.

Pat, do this first !!!!!!!!

Check that there is NO water in the O'2 connectors. (blow out with air) Go back and remove the "ground cable" from the batt. ( I don't know if your radio needs a code to restart, but find out what it is before you do this!) Wait about 5 mins. and put the cable back back on. Reset all of your radio stations :-) and start your car. " IF " the code comes back, then go start looking at other items to cure the problem.

Removing the cable, lets the computers reset themselves and many times that is all you need to do.

Good luck and I hope this helps.

Bruce Bing '03 LS

Bruce,

Will do as long as you can point me in the right direction. How do I access the O'2 connectors and recognize them. It's not in the index of my workshop manual. Could they be called something else? I didn't find anything in the miata.net garage to help. Are the connectors hoses or wires. Sorry for all the questions. I don't know where to look.

Thanks,

- Pat

I don't know how may miles are on your 99. The 420 code can be caused by misfiring, which can kill the converter if not corrected . It also is sometimes caused by a bad O2 sensor (front or rear) Since the front sensor is more likely to fail than the rear, and if everything else has failed, Try replacing the front sensor before you spring for a converter.

Or you might try this one.

Now you need to clear your 'Check Engine' light. There are a couple of ways to do this. The easiest is probably just to pull the BTN1 fuse in the fusebox located under the hood on the passenger side for about 30 seconds. If you pull it out too short, you won't reset the code. If you pull it out too long, you'll lose your radio presets.

Until I purchased a code reader of my own I used to havce to do this regularly and I never lost my radio presets.

To be honest, you can buy a code reader of your own for about what Mazda will charge to reset the CEL once. Considering that something as simple as not tightening the gas cap (do you ever have someone else pump your gas?) can turn it on, it is a good thing to carry int he glove box of a Miata.

bill

Thank you all for your advice & wisdom.

I did a two step replacement of the Plugs & Plug Wires. I purchased plugs and wires from Autozone. The more expensive ones. The next morning I disconnected the battery and replaced the plugs. Couldn't replace the wires because the #1 & #2 replacement wires were too short! I reinstalled the old wires, reconnected the battery, returned the autozone wires and drove to NAPA. The check engine light stayed off! Problem fixed. At NAPA, I asked for their set of wires and found them to be too long!

Later that day I purchased wires from Mazda. They too were a little longer than the originals. These are working fine, the check engine is off. Not sure the wires really needed replacing, but @ 65K it's the safe thing to do.

It gives a great comfort that this news group is here! Again, Thank you all.

- Pat

P.S. Next "Service" I have to concern myself with is the Timing Belt. I'll let Mazda do it unless someone has a recommendation in the Plano, Tx area.

Check out cartalk.com. They have a link on their site where you can find a good shop in your area.

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

Glad that I am not a mechanic type. I would have just paid the 200, 300, or 400, whatever dollars at been done already>LOL.

P.S. I had been searching for a suspected very small coolant leak on my

94 Chevy S10 P/U, with only 48K origianl miles, for over 2>3 yrs.. Could never find anything. It was so small, I was thinking that since the overflow bottle is not a closed system that it was just evaporation. My Wife and I were both detecting the smell of coolant. But I figured we were smelling the fumes rising from the overflow bottle. Finally I saw some drops hanging off the rear right bottom of the engine. AH HA finally, I see something. Took it to the shop nearby, not knowing what to expect since I could never fine a leak anywhere, hoses, radiator, whatever. Turned out to be the head gasket, costing me over $1,400.00 which I was told by a very close friend that is really into cars, that that was really cheap.

FIXED!!!>LOL.

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!