Had 18 codes this morning. Too many to list but had random misfires among other things basically car has 94000 miles. changed plugs/wires and new gas cap installed. The car started fine and idled around 700 also good after doing this. To clear codes and see which were still remaining i was told to unplug the battery and remove two main relays. After reconnecting the battery and inserting main relays, car now will not start. It turns over but immediately kills and check engine light is flasing now. I realize i havent given a lot of info but i am hoping someone recognized what happened. Would appreciate any input!

 

I hope you disconnected the battery first before removing relays and inserted relays first before re-connecting the battery. If not your relays may be screwed. It also may have not been enough as another member recommends applying brake pedal after disconnecting battery to suck any leftover juices.
Removing relays was not necessary at all, just applying brake pedal would have sufficed as well as leaving battery disconnected for 10 minutes before re-starting and let idle for 10 min. I hope your computer doesn't need re-flashing (just guessing as a possibility).

 

Sorry for the delay getting back, very busy. Thanks for the input. I never would have thought of the brake to drain the system. I did remove and replace the relays correctly on someone's advice but using the brake definatelly sounds like better advice for the future.

After crossing several possibilites off the list I was left with a timing issue or a vaccuum leak. Since I didn't have a smoke testor or the tools to do the timing I took it to the shop and it was indeed a vaccuum leak underneith where I could not see. It must have been leaking slightly earlier causing some of the problems. One other thing we did is remove and clean the EGR valve which required removing some of the hoses. May have made the leak bigger when we were doing that I guess.

 

That was a lot of codes. Too many to deal with. WOW. Vac leaks are common. Good Job! It's always wise to start with the small cheaper things before resorting to O2 sensors or ECU or cats.

 

It was amazing how many of the codes were removed just by replacing the gas cap for $12. A big thanks to my neighbor. Just a little tip for anyone who happens to read this post string.

 

Hi guys, does anyone know if my 2002 Mazda 6 Classic has a timing Belt or chain???