check engine light goes on every 100kmh on hwy

snooze · Post by **snooze** » July 30th, 2007, 2:09 pm

Hi folks,

I am writing again about my 93 v6 mx-3. To update you guys, i finally got the A/C working, I found a shop that has the R12 refrigirant and they installed the gas and everything went great!!! that's a bonus. Now for another problem.

Everytime i drive the car on the hwy, and reaches speeds to about 100+ kmh, for about 10-15 minutes, the "Check Engine" light goes on, if i turn off the car, and turn it back on again, the light doesn't come back on. Only on the hwy it does this. Does anyone know what the problem is associated with? I took it to Mazda and they won't do any further diagnostics cause they said that if it's a soft code, it won't store it in the computer, and they couldn't pinpoint the real problem. If light stays on even after turning the engine on again, then there's a problem. They already replaced the EGR valve and said it should solve the problem, but still, the engine light comes on, some mechs said it could be the oxygen sensor, or cat converter. Any ideas everyone? I just had this engine replaced and it's cost me a lot already, but now, i just want to fix this engine light coming on and that should be it.

Should i take it for emissions test to see if it will pass? Any suggestions?

Many thanks to those who can help.

Thanks,
snooze

ninjajim4 · Post by **ninjajim4** » July 30th, 2007, 2:48 pm

you can check yourself to see if the codes stuck:

http://www.mx-3.com/phpbb2/viewtopic.php?t=34787

snooze · Post by **snooze** » July 30th, 2007, 2:58 pm

i really appreciate the reply on that ninja, but i'm no mechanic, and i would have no clue how to even work out the instructions you posted, plus it doesn't even have images for me to see how it works, so it won't mean anything to me at all.

thx though,
snooze

Tunes67 · Post by **Tunes67** » July 30th, 2007, 3:21 pm

Seriously snooze.. if you cant, from the instructions in that link, figure out how to pull codes.. then there isnt going to be anything we can do to help you here. Thats pretty much the simplest and one of the most fundamental things you will need to be able to do with your car to be able to diagnose most any problem. If thats beyond you. You'd be better off selling the car or just taking it to a mechanic. Best of luck.

Tunes67

PATDIESEL · Post by **PATDIESEL** » July 30th, 2007, 4:26 pm

Harsh, but true. By asking a question on a forum like this you are asking us to help diagnose a problem that we cannot see or hear. You have to be able to at least start the diagnosis in order for us to post any meaningful suggestions. That said, if you cannot help us help you, then we cannot help you at all.
Again, why are you taking the car to Mazda. The Mx-3 is old and the mechanics there are used to working with much more "intelligent" cars. Newer cars are much more mechanic friendly when it comes to finding out what it wrong with the car b/c the newer cars have so many sensors and much more complicated computers that can tell when a sensor detects a problem. You need to find a good, trustworthy mechanic in your area to take your car to when you have a question or problem. Ask friends, your parents or other local MX-3.com members where they take their car and try that route instead of the Mazda dealership.

snooze · Post by **snooze** » July 30th, 2007, 4:56 pm

ok guys, i tried it, and i got a 1 blink on the 10s and 6 blinks on the 1s. which resulted in 16 - EGR System. Is this accurate? I tried it many times, and it gave the same result. Also, the dealer just replaced my EGR valve. What the heck what is it now with the EGR system?

Snooze

Tunes67 · Post by **Tunes67** » July 30th, 2007, 5:14 pm

I suppose its possible that the dealer didnt clear the ECU of codes after he finished with the repair. So thats what I would try first. Here is how you clear your error code(s) from the ECU.

1) Disconnect the battery for approximately 10 minutes.

2) Pump your brake pedal 5-6 times (this will discharge any remaining current or charge left in the cars electrical system)

3) Reconnect the battery.

4) Start and run the car.. even try taking it out onto the hiway and see if it will throw the CEL when you reach 100khm.

If it does throw the code again.. report back again and we can see what the next step to try will be.

I didnt mean to sound harsh before, but as Pat alluded to.. we cant help you if you cant (or wont) help yourself. Cheers and best of luck.

Tunes67

snooze · Post by **snooze** » July 30th, 2007, 11:53 pm

hey don't worry, i'm open minded when it comes to this. It would be stupid of me to even feel bad when here i am asking for help.

I will try to disconnect the battery and do what you say, and will let you know the progress. I spoke to my mechanic about this matter, and he said that if it's error 16 then it could be the intake manifold that's causing the problem, but he said he will still look into it. He said that it could be clogged or it doesn't have the proper sealing, since it is related to the EGR System (ie exhaust etc.)

Thanks,
snooze

midrange · Post by **midrange** » August 2nd, 2007, 8:11 am

well, i read this from start to finish...

I am having the exact same problem with my gs. My engine light only comes on when doing 80 + km/h... And only once and a while, not every time. I do the same thing, i turn it off, and back on again and the light never comes back on.

MY TRUSTORTHY mechanic siad the exact same thing, either o2 sensor OR cat converter.. This worried me as i had to get it etested a couple days ago, but sure enough, my car passed fine but i had no check engine light on at the time. only at higher speeds.

My first judgement after reading about this, is I may need better spark plugs as my spark my be weak for the faster burn, which is causing bad burns meaning the o2 sensor is reading rich or lean mixtures. But now this can reflect to the intake manifold you mentioned.

So, i shall wait until whatever problem it is becomes more serious because like you, i turn my car off, and it doesn't appear on again and i'm fine with that..

Also, not arguing, but i know that 30 seconds of a disconnected battery will clear codes.. Done it many times clearing the codes each time.

Tunes67 · Post by **Tunes67** » August 2nd, 2007, 10:47 am

I always overstate how long to leave the battery disconnected.. so there is virtually no chance that the ECU will still have a code left. Its exaggerated purposefully for those that dont do it on a regular basis.

Tunes67

Yoda · Post by **Yoda** » August 2nd, 2007, 1:29 pm

One the older OBDI cars would it be easier just to disconnect the Positive battery cable from the battery and touch it to ground. Instant discharge of the caps and codes.

I also have had similar problem once that turned out to be a poisoned O2 sensor. At the best of times the O2 sensors start to read slow after about 80000km especially the rear one on the V-6.