2002 SE Manual 90k miles.

I was driving and the SES light started blinking and I knew what that meant. I figured a coil that was covered in oil a while ago was done for but then I checked the code and its multiple cylinders (I also have p1147 02 sensor).

Ironically, I was reading a thread not to long ago about battery life and noticed my car has the original battery! Does it make sense that an eight year old battery would still start my car fine (even with subs/amp) but cause a misfire? Also, I believe P1147 is low voltage reading. Is it possible that could just be due to a poor performing battery? Either way the battery will be replaced today.

Not sure if this is a basic question or not but thanks in advance for all your help.

 

I've never seen a low battery cause a misfire, or any other codes.
PO300, GL with that. Sounds like you may be on the right track with the coil(s). I recommend replacing them all with that kind of mileage. Also check your plugs.
As far as the O2 code, clear it and see what happens. If it returns, replace both your downstreams (or splice in an 02 sim).

 

Yeah I've never heard of a battery doing it either but it seems random that multiple cylinders go out at the same time. Replaced the spark plugs 20k miles ago. Thats when I noticed the oil leak and the #5 coil covered in oil. Luckily I moved it to the #3 spot in case it died.

The 02 sensor code has been there for like 6 months haha. Other money things have popped up every time I think about buying the sensor. After I change the battery I'll go from there. Thanks for the response

 

Replaced the battery, still a little off but not as bad. I bring it to a mechanic to CHECK which coil, if any, was bad. Coil #2 is bad. I never asked him to replace it but he did, for $140, "but it was originally $190." Never asked me just did it. I tell him no thanks and he gets all angry, didn't want to play these "games." People like this anger me

 

That's what the economy is doing to people these days. $140 installed is not a bad price I guess.

 

It's one thing for him to take the risk and replace it (hoping you would simply be satisfied w/ the end result) but I don't understand why he'd get upset. Just curious...

 

I imagine it was more of a tactic to get me to pay.

and $140 installed is not that good considering the install takes about 5 mins

 

I just went through the same thing. My #5 coils was soaked in oil and was causing a the p0300 code (misfire) I had all the plugs replaced and the coil replaced. Didn't have the front and rear rocker covers in stock so I had them ordered........

 

What about the time it took him to diagnose the problem?

 

My o2 sim just went out........... I think you may need a different route to go through with the o2 sim since i heard they were out recently...

 

$140 for diagnosis and replacement of a coil is *reasonable* price. You could have changed it yourself for may be half of that but that is immaterial.

Generally an hour for diagnostic and replacement is very fair. Shop will (and should) have its own markup on the part. Considering all, $140 is cheap.

He is a good mechanic and you did not treat him well :-(

- Vikas

P.S. In general, shops/mechanics are crooks unless proven otherwise. In your case, he has proven to be NOT a crook.

P.P.S Why did you not check it yourself which coil was bad? What price do you think would have been fair for him to diagnosis and tell you which coil was bad?

 

I love you sig Sweet and to the point. And your Max looks nicely done. Great job.

 

That's exactly my point. Being in the business, I can relate to this. People never think about all the time it takes to figure out the problem. They just look at the time it takes to change a "five minute" part.
Think about it. That coil probably cost him 60 to 70 bucks. He spent a good hour hunting down which coil was bad. With the markup and everything, no wonder he got mad.

 

touche, didn't think about that part I guess. I was to busy being mad that he did it without asking me. All in all I would bring my car back to him. This isn't my first experience with him.

p.s. He said the car was to fast for him. Makes me like it more

 

I have been dealing with a code P0300 and rough idling, and a horrible misfire that would come and go. Changed the plugs, fixed a loose ground cable from the battery to the tranny, cleaned all the injectors, tested the coils. The mechanic told me the next thing to try would be a new computer probably about an $800 job. Well I have noticed lately that I wasn't getting much heat from the heater so I mentioned that to the mechanic. So he changed the thermostat and cleaned some corrosion off the battery terminals. SES light is gone and no more skip. I have put about 200 miles on so far and it still has not come back. Not sure if the thermostat was the problem but I would definitely make sure you have a strong battery and the connections are good. These cars are very tempermental!