check engine light

easysurfer

Give me a museum and I'll fill it. (Picasso) Give me a forum ...
Joined
Jun 11, 2008
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Yesterday the check engine light came on my car. I brought it in to a Car-X. They said the error code showed a "misfire" (cylinder), but the car fired up fine this morning. They reset the light and said no charge :D, if the misfire happens again, bring it in for another look.

I had thought, oh no, probably about $200 more of service (some places charge about $100 just to hook up the car and grab the error code).

My thinking has changed since retirement. In the past, I would have really pursued to find out why the misfire (I actually think, the outside weather as it was parked outsid in the cold). But since retiring, I think ..Great, no charge :D
 
If you've had a missfire on one of the cylinders than there's a chance it will come back eventually due to worn out wires or spark plug. Keep an eye on it and see if you can diagnose which cylinder is causing the problem
 
If it does happen again , I would strongly advise to pursue the cause. It has to misfire for some time before the computer latches the [-]check wallet[/-] check engine light. Misfire over time can fry a catalist , and an OBDII cat is not cheap.Then it really becomes " check wallet ".
 
If it does happen again , I would strongly advise to pursue the cause. It has to misfire for some time before the computer latches the [-]check wallet[/-] check engine light. Misfire over time can fry a catalist , and an OBDII cat is not cheap.Then it really becomes " check wallet ".
I thought I was fairly "car literate". What's a catalist? Is it like a catalyst? I have an OBDII reader but it doesn't do a cat scan, what's an OBDII cat:confused:?
 
The check engine light is on in my car, too. It has been on and off for the last 2 years. The code is P0420Catalyst System Efficiency Below Threshold. The mechanic I go to doesn't seem to be too concerned (but it did cost me $60 to get the code read). I am ignoring it for now since it feels fine. I think it's either a faulty O2 detector or a catalytic converter. I don't know if ignoring it is the best way to deal with it but it will cost another couple of hundred just to ascertain the problem.

They should seriously change it to "check wallet." Much more accurate. :nonono:
 
The check engine light is on in my car, too. It has been on and off for the last 2 years. The code is P0420Catalyst System Efficiency Below Threshold. The mechanic I go to doesn't seem to be too concerned (but it did cost me $60 to get the code read). I am ignoring it for now since it feels fine. I think it's either a faulty O2 detector or a catalytic converter. I don't know if ignoring it is the best way to deal with it but it will cost another couple of hundred just to ascertain the problem.

They should seriously change it to "check wallet." Much more accurate. :nonono:

Last summer I found out that Autozone will read the code for the "check engine light" and tell you what it is, for free. Of course, if anything needs to be repaired, then you would probably have to pay the repairman to read it again. But in the event that it is due to a loose or faulty gas cap, you wouldn't have to pay the $60. Hope this is helpful to somebody at some point.
 
The check engine light came on in my pick-up several months ago, just a few weeks before I needed to take it through DEQ. I took it to a local shop and they read the code and turned off the light. They told me it was a random misfire on cylinder 3 and to just drive it and come back if it happened again. The light came on again a couple months later and then went off again during the day as I made several trips around town. I've decided not to worry about mine for now. It is registered for another 2 years and seems to run fine.
 
I bought a code reader for about $40 @ Harbor Freight, comes in handy as I have an old Jeep I keep running. It is good to know the nature of the code, some are much more serious than others. And in California you need to have no CEL on to pass the smog check. The reader will reset the codes which will help if it is a random event.
 
Yakers, pardon my ignorance about cars, but how do you read the code? Do you connect the code reader to the car and the code pops up? I know this is really dumb but I know close to zero about cars.
 
I thought I was fairly "car literate". What's a catalist? Is it like a catalyst? I have an OBDII reader but it doesn't do a cat scan, what's an OBDII cat:confused:?

I think I need to use a spellchecker :blush:. I did mean catalyst. The catalyst ( and many newer cars have 2 , one near the exhaust manifold and one further back ) on cars with the OBDII systems are quite co$tly.

W2R sure has the best first step , the free codereader use at Autozone.
 
W2R sure has the best first step , the free codereader use at Autozone.

They don't just let you use it - - they do it for you, give you a print-out of the code which also prints out the reason, and they give you some interpretation of what that means if the reason isn't self-explanatory. Then they informally discussed it since I know zero about cars. So, they do just as much as your mechanic would do for you when he reads the code, or more. Only they do it for free.

But then, if it turns out that something needs to be fixed, you still have to take it to your mechanic who will probably want to read the code for himself, and charge you for it. I took mine to the dealer, who refunded the cost of reading the code since I had them repair it.
 
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+1 on autozone or advanced auto parts. FREE

It could be simple like plugs or wires, but most likely need a fuel injection cleaning, or like on our mustang, the whole frigging fuel injection system needed re-done.

I'll keep my fingers crossed 4 ya...just let it go!
 
Yakers, pardon my ignorance about cars, but how do you read the code? Do you connect the code reader to the car and the code pops up? I know this is really dumb but I know close to zero about cars.
Yes, you connect the wire off of the OBD1 or OBD11 or other scanners as in Tech 11 etc. to a harness (plug) which on some cars are mounted below the steering column in the center. Depending on which model scanner you have it will give you a code only or actually tell you more details of the reason the light came on at one point in time. Some scanners will allow you to change certain perameters on your cars computer but we won't get into that at this point.
If at one point the service engine light goes off it doesn't always necessarily mean the problem is solved it just may be that the problem isn't as bad at that particular moment but it's still stored in the cars computer unitll cleared by either a scanner or disconnecting the battery for a short period of time. Keep in mind that by disconnecting the battery on certain vehicles it may need to recalibrate the computer on it's own after about 100 miles.

For those that think the car is running fine with the engine light on, it could be that one of the oxygen sensors has gone bad and is not comunicating to the fuel injectors the proper fuel air mixture and you're not getting the best fuel economy. This could possibly cause problems for the catalyic converter, which won't show up for years to come.
 
I notice an intermittent miss at idle, usually before the computer catches it.

SOP is

1. new plugs
2. If it still misses, change the plug wires.

So far, this has worked, and for minor amounts of money.
 
Easy fix, from the Value Menu:

:D
 

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Easy fix, from the Value Menu:

:D
:LOL::LOL::LOL::LOL:


Just what I did on one diesel Jeep I have, one part is intentionally disconnected and gives a CEL so I have to check codes periodically to make sure nothing else is amiss. Its OK to ignore the CEL if you know the code, the cause of the code and check it regularly.
 
For a mere one-time $98, you can analyze this situation yourself on all of your vehicles (built after 1996) now and in the future.

CarMD.com
 
2001 Honda Civic has had the check engine light come on twice. I forgot the reason it happened several years ago, but this time I took it back to the dealer and they charged me $99 to tell me someone hadn't tightened the gas cap at the last fill up. Then I remembered that was why it happened the previous incidident. Couldn't yell at my wife because I'd filled her car up the last time. Later on that week, I inadvertently put Metamucil on my cereal instead of sugar substitute. Getting old ain't for sissies!
 
The light was on for the last week or so in my 2006 Hyundai Sonata with 90k miles. Dropped off at the dealer today and they replaced the intake air gasket due to a leak. To my surprise it was covered under warranty and they only charge me for an oil change that I requested.
 

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