I got the check engine light lit up on my 99 miata, i read previous "check engine" light posts and they said to try putting the gas cap back and tightening it and then remove the battery cables from the battery for like 30minutes then put them back on then the light should go off. Ill try this tommorrow but for the time being i got another question, is there any site or book i can get that has all the check engine codes and has what each code means or do i have to go to the dealer to get it checked, if that battery thing doesnt work tommorrow i was just going to go take it to autozone because everyone is telling me they do free checks on that kind of stuff.

 

There are over 90 Diagnostic Trouble Codes for drivetrain. Best try AutoZone as you'll need a scan tool to read DTC's. There are
books available, since the fed's make the auto manufacturer's standardize the DTC's numbers to a particular fault. However, the
diagnostic procedure can very by manufacturer.

 

oh ohkay kool so ill just take it over to autozone then, thanks

 

came to found out that the CEL was lit because of a catalytic converter malfunction, anyone familliar with that kind of deal? does it need to be replaced? is it broken? whats going on?

 

So that would be a code P0420 or P0421. Catalyst efficiency codes are not that uncommon. The engine computer tests the efficiency of the catalytic converter on a regular basis by federal laws and if it fails the test the light will come on with one of those codes stored. It is unlikely that it was a one time glitch as the test needs to fail two times in a row to turn the light on. Replacement of the converter is really the only way to cure this problem. Don't forget that your factory emissions warranty is 7 year/70,000 mile for california spec and 8 year/80,000 miles for federal spec vehicles. If you are still within this time/mileage then Mazda will replace the catalytic converter free of charge to you.

 

Have you had any other problems you 99? If you ever have a coil pack failure, it will take out the cat and the o2 sensor(s). Mazda won't replace the coil pack, but they will repair you exhaust free of charge as long as you are still int he 8yr/80000mi warranty period.

 

im not sure if the warrenty still applies 7/7k or 8/8k because im the second owner of the car so i bought the car used. As for the coil failure im not sure of that right now but as far as the catalitic converter i think it has to be replaced and in the process of doing that, thanks for the info on the problem i was getting alittle worried about what was going on. Another question for ya tho, if the cat isnt working property to its standards, will that decrease the overall performance of the car? Im guessing yes, but i dont know alot about cars like you guys but im always down to learn little things here and there about my car. I know for a fact that im not applied to the 7/7k plan because i passed that barrier already

 

i think the check engine light comes on in every car randomley, so you have to take it to the gararge and pay to have it turned off, sounds like a scam to me, because it happened multiple times to me and my ford taurus i use to have

 

A catalytic converter efficiency problem usually should not create any performance problems unless it is plugged up which would cause a restriction to exhaust flow and decrease power on acceleration.

 

my check engine light came on, i took my car to the dealer and was told a downstream 02 sensor died... i replaced the sensor and the CEL still comes on every hundred miles or so.. now i am told the catalytic convertor is perhaps losing its efficiency...so a local muffler shop is replacing my cat converter nect week with an after market brand which will save me mega dollars over the dealer's price... hopefully, that's my problem, although the car runs perfectly and gets great mileage.