[TE]

So a couple days after I got my car back from the 60K service(timing belt, etc...) the SES goes on for the first time ever. On the weekend I bring it to the garage again. Guy calls and says the SES isnt on anymore :wtf:. I say ok and take it home, thinking he cleared the code and was jerking me around. Couple days later SES light back on. Then a few days later off again. So Now I am pissed off. Instead of going to autozone to get the code read. I go order a good ODB2 reader. Couple days later the light goes back on. This time I am ready . I pull the code. Its P0300. I after a quick 3G search I learn this is a generic code and could be a bunch of things:sad:
So when I bring it to the garage this weekend what should I suggest the dude to check first?

Also I assume since the light goes off and on and the car seems to drive like normal its not a major problem and I will not be hurting the engine driving it around?

 

[Bitter]

dont worry unless it blinks but do fix it.


random misfire (which you know) can be any number of things, make sure all the plug wires are tight, plugs are correct, no air intake leaks or intake manifold leaks, etc. might help to tell him the conditions which set the code, accelerating, stopped, slowing, shifting, etc.

 

[TE]

thanks
I didnt know SES light could blink. So I take it blinking is a sign something is really bad?

 

[Bitter]

thanks
I didnt know SES light could blink. So I take it blinking is a sign something is really bad?

blinking is very bad, catalyst damaging bad. when it blinks it means that the misfire or other problem is soo bad that the converter or engine could suffer damage...its not pretty. we were troubleshooting a car at work the killed off both of its brand new cats, previous shop just put on new cats and cleared his codes rather than fixing the problem, hooray for morons!

if its coming on and off it means its setting and clearing itself so its just barely meeting the criteria to set...meaning it may be hard for them to track down. just ask them to double check everything that they did because you've never had the light on before, if theyre good guys they'll understand. might help if you make an appointment so they can set aside some time to check it.

 

[MarkSpyder]

I am trying to troubleshoot my own P0300 right now and can say I have heard it can be related to the following:
- bad sparks or wires
- bad distributor rotor and/or cap
- oil getting into spark tubes (bad tube seals)
- CPS sensor going out
- air/vac leaks

So far I have replaced my seals and checked the sparks but no luck. I just ordered new distributor parts and a CPS to see if one of those is the culprit.

 

[TE]

and the SES light just went off this AM:lol:

 

[MarkSpyder]

From the sounds of it I would expect to see your SES light up again soon Mine went off and on a few times by itself at first. Now it comes on almost immediately after I reset it.

Did they replace your plugs, wires, distrib parts too or did the just stick to stuff on the timing belt side (belts, pump)?

 

[Bitter]

scotty, is there any pattern to when it comes on? only when the car is hot, cold, warming, up, accelerating, decelerating, etc. information like that is a big help to determine the source of the problem.

 

[TE]

Cant be sure the other times. But the last time it came on, was when the car was first started and was idling for a minute or two
Also the car seems to idle a little rough at times

As for what they did. I just gave my mechanic the service book from the car, and told him to do everything on the 60K list
My whole family has been going to this garage for 15+ years. They know us, and we have a good repour with them. They do good work(in my experience)

 

[Bitter]

alright, the roughness is for sure the misfire. it could be unrelated and just coincidental, but that would be odd. hard to tell without putting hands on it.