klseiverd, I hope you've had periodic maintenance done on the various parts of the car as recommended by the manufacturer. If so, you should take the car to that shop and have them advise you what should be done.

Catalytic converters can be damaged by other engine issues, so there's no reason to guess about it. 12 years sounds like a long time on the original one. The Scarlett O'Hara route is no more than sticking your head in the sand - if there's a problem, it won't go away by ignoring it.

lindylu, she said the error code had been read. Maybe incorrectly, it's not like people at a parts store do that regularly.

A faulty battery triggered the CE light on our car. New battery, check engine light went out. Our mechanic said it happens.

If the light came on because the battery ran down or was disconnected, and if the battery was replaced or the old one re-charged and the fault no longer exists, the light may go out after a certain number of starts with no fault code. This should be explained in your owner's manual. Various systems behave differently, so check your owner's manual or a repair manual if have one.

I don't understand why you didn't replace the obviously weak and dieing battery. That in itself can cause problems that can trigger a check engine light. It doesn't sound like the person that did the diagnostic was sure what exactly the problem was. I would go to a dealership or reputable repair shop and have a technician that does diagnostics daily run the tests. Ignoring it will likely end up costing you more in the long run. And could leave you stranded in a bad situation and paying for a tow service.

I hate when my check engine light comes on. If they can make a car that tells that... why can't they make a car that actually tells you "just what the he!! is wrong? I drive with mine for a while at times... but eventually take my car to the dealer and let them tell me, what's wrong. Then I still have the option to do what ever needs done right away, or hold off.

Moni

The last time I took my car in for an oil change I mentioned the Check Engine light had been on awhile. Like lindyluwho mentioned this happened twice to me and was the gas cap, altho I couldn't see that it wasn't on properly or whatever. Anyhow, I asked the guy at the garage to have someone check the reason for the light just in case. He said, "Ok". Then hands me the pre-invoice before they take the car back for the oil change and the "diagnostic check" is $90! I said forget it. They've done the test free for me twice in past years.

I've heard the "Check Engine Light" also referred to as the "$300 light" because whenever it turns on, the cost to fix whatever the problem turns out to be will usually be somewhere around $300.

Regarding the "Diagnostic check:" fee if all they are doing is connecting the Code reader to the ODB port and simply telling you what the device says, its ludicrous and borderline criminal IMHO for them to charge $90 for it. If they are actually doing further work to figure out what the problem actually is then it may be reasonable. As I understand it, the Code reader essentially tells the symptoms the car is experiencing, and just like with people, a given set of symptoms could be caused be a number of different underlying problems.

Yeah, his answer to me was, "Well if we can't check it then we won't know what's wrong with it". I think on one occasion it was just a fuse, found with the Code reader.

This same place rotates my tires every so often, included in the oil change, etc. I always check the lug nut caps because here again, on three different occasions (one at a tire shop, not this dealership), when they took the tires off they broke the lug nut caps. The tire shop tried to tell me someone probably stole them while I was parked in a parking lot! I suspected not and argued. The manager gave me free caps and labor. The last time at the dealership, I paid for the caps and got the labor for putting them on free.

This time, when the car was driven out, I brought up the lug nut caps. The guy looked out at the car and says something like, "Yeah, looks like some are missing". I asked him if it was possible they broke them because I checked and all the caps were on before I drove it here. He said probably, if they are old, the caps break easily. BUT - he wasn't going to tell me the caps were missing until I brought it up. So I had to buy four caps at $10 each.....I just stared at him. grrr. He asked if I still wanted them - yes, I do. They had to order them. This was two weeks ago, no phone call yet. I have a mind when I call to see if they came in, to speak to a manager and see if I'm going to have to pay labor and if so argue my case.

Sorry, to hijack your thread klselverd.

My CE light came on a few weeks ago...told service man when went for routine oil change etc.. He put it on a machine to check and said I had a weak thermostat and it was up to me if I wanted to replace it....I did because I do not want it to over heat on a hot summer day.

A CE light comes on for just about anything...low oil...low battery. A battery can be low because the alternator belt is slipping, not necessarily because you need a new battery. A catalytic converter......weeeeeell.....a lot of people don't use them or put them back on if they go bad now an emmisions test is not needed.

Mine has come on just from being overdue for routine service, not because there was any problem with the car.

If the low battery triggered the CE light to come on then you cannot trust what it said when you put the diagnostic tool on it. My neighbor is a "shade tree mechanic", he told me to take my car to Auto Zone to put the tester on it, they do it for free. He works at Auto Zone.

Your car is usually your second largest $$$ purchase, after your house. Why would you not want to keep it in good running condition? Just doing basic maintenance will keep 90% of all cars sold running for at keast 150,000+ miles these days.

My 2010 Ford Fusion showed an engine light. But then it went off before the shop could check it. I brought it in anyway (since I had the appt) and the rep said, "If it sounds okay when you're driving it (which it did), I would recommend NOT spending the $158 for the diagnostic. It could be just a bad sensor instead of an actual problem. If the light comes on again, just bring it back."

About a week later, the engine light came on again and stayed on, this time. I dropped it off, and it turned out to be two solenoids that controlled the camshaft timing. Since replacing these involved some disassembly, I left the car with them for two days.

Ford had also issued an advisory about possibly fuel tank cracks, so they also removed the fuel tank to check for any problems there.

Because the car was still covered under the original factory emissions warranty, the diagnostic and all repairs were completely covered.

Had I waited, I might have been past the warranty period. So it was a good thing I brought the car in when I did.

My check engine light is always on. We've tried everything. The previous owner is a mechanic for Land Rover and he used a computer on my truck to try to figure it out. It'll shut off when he's done, but wait 24 hours and it's back again. The gas cap is secured. The battery was replaced. The oils and are topped up. Nobody can figure it out. It's been that way for over 4 years.

My DH has been a auto tech for over forty years. I asked him about your problem. He says it will likely be just fine. Apparently as a car sits over time the gas looses its volatility and can contaminate the oxygen sensors, by introducing fresh fuel the sensors get clean and let the computer know that the cat converter is working properly now. It would be VERY unusual for the light to shut off if there was a another problem.

Guy i date is mechanic and told me check gas cap and also it may be emmissions. Which i passed so i wasn't worried. He said there is no danger with driving with the light on. Mine stayed on for 23 weeks and last night he plugged in this "dohicky thing" and turned the light off for me.

My check engine light came on last winter and I was concerned. Never dealt with that issue before so I had no experience. I did some research and found a lot of variables. I remembered Auto Zone would read them for free so I went there, they were real nice about it, read it and printed out a list of things. The code was ambiguous and the list included recommended maintenance for the vehicle which was handy. I knew my battery had tested weak at the last oil change and they wanted to replace it but I wasn't spending $130 there for a battery. It started fine but I did have a time or two the previous winter where it turned over slowly but since it started I was in no rush to replace the battery. Found one on sale, bought it, but still haven't installed it. I'll do it when the weather is nicer. Auto Zone then reset the light and I went on my way. More research said oxygen sensor which could come from a loose gas cap. Another issue I started finding was that the battery was weak. I'm going with that. And the light came on again, but went off after a couple weeks. It's back on now. I'll be replacing the battery soon so as Penny on Big Bang Theory puts it should put a piece of tape over that light.

I'm not going to lose any sleep at this point and I don't think you should either. I sense that the problem will end when the battery is replaced (on both of our vehicles).

As a side note, you have to be careful with mechanics. Find one you trust. I went to my sister's favored repair place with a shaky front end and they wanted $50-$75 to just bring it in. That was doing NOTHING. THEN comes the diagnostic fees of an estimated $200-$300 and that's diagnostics ONLY. More if it takes them longer to find the problem, THEN come the repair charges. The only reason I went there was that they were open on Saturday and my favored mechanics were not and I wanted to get it done. Plus, to top it off, there were no cars being worked on and 3 guys standing around doing nothing but I needed to make an appointment for later in the day to get it looked at. However, if I wanted an oil change they'd do that right away. I made the appointment but got more irritated on the way home so I called and canceled the appointment and took it to my usual repair place who always give free estimates. As it turned out I needed an alignment and replaced tires, all of which cost less than $400. So for what the other place would charge in fees and diagnostics, I got new tires and repairs. Needless to say I'll never darken the door of that other place again. And I didn't need an appointment with mine. They go first-come-first-served and I was there at opening so it was done in a couple hours. Reminded me of the value of honest and competent mechanics.

A few yeas ago I learned the difference between the check engine light being on, and it flashing. (Short answer - the difference is several thousand dollars)

When it happened I brought the car to a local shop I had used before and happy with. They pulled the codes and could tell something was very wrong with cylinder 3, but suggested I go to the dealer because perhaps the dealer's code reader could give a more detailed description of the problem without doing expensive dismantling and diagnostic work.

The dealer's mechanic said "The codes say something is wrong with cylinder 3, but we'll have to pull the engine, and tear it down to determine what. Doing that will cost $2500, and then any repair work would be on top of that.

I called the local shop, and they said "If they are charging that for the diagnostics, it will likely be well above $5000 before they are done. We are pretty sure what the problem is, and could do the entire job for less than their diagnostic fee."

I brought it back to them, they pulled the engine, tore it down, discovered that one of the valves in cylinder 3 got stuck open, and the piston beat it to pieces, fixed that, and reinstalled the engine for a total of about $2300. They even replaced the timing belt, which needing doing in about 10000 miles, and normally costs about $1200 just for that.

Of course they have since gone out of business, I guess being honest and competent doesn't pay very well.

Honest and competent pay well when people know about them. However people keep patronizing the crooks for some reason. Can't figure out why my sister keeps going where she does. Well, I guess I do. She's stubborn and doesn't like change. And the place is the location of where she bought the car. The dealership went out of business when the cars were no longer manufactured and it became a used car lot. Doesn't that wave a HUGE red flag?