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21

You've come to the right place. There's a lot that you can do on your own. Even if all you end up doing is gathering more information for the mechanic who ends up working on the car, they never mind a hint as to where the problems might be! What are some of the possible causes for the "check engine" light that can be diagnosed at home? All of them. ...


16

There are two possible explanations: If the fuel cap does not form a good enough seal, the fuel injection system may experience problems with drawing fuel from the tank. On newer cars many of them have a fuel cap sensor to detect if the cap is not screwed in. This is related to emissions, although i am uncertain how. I know when I get my yearly emissions ...


10

A Set of Standards for Error Codes I'm sure that someone is going to come up with a much more exhaustive answer, but for a good start, you need to understand that there are MANY different standards for reporting vehicle diagnostics. For example, take a look at the OBD II Pids Article on Wikipedia. Think of your car's computer as only as powerful as the ...


9

For checking codes, any off the shelf obd2 reader will do. If you want to have fun, ELM327 based OBD2 readers are all the rage right now. You can pick up a bluetooth version for ~$40 on amazon or ebay. Several iOS and android apps (like Torque) exist that can read a signal from these adapters and do full on data-logging. This will let you read/clear ...


9

The EPA regulations require that the fuel tank is a sealed system so that no vapors escape. There is an entire system (Evaporative Purge) dedicated to that task. EPA regulations also require that the ECM (Engine Control Module) check they system for leak. When the right conditions are met IE fuel level between 1/3 and 1/2 tank, outside temp 50 - 90 etc. the ...


8

It was indeed the catalytic converter (the EX does not have a pre-cat). After replacing it, the downstream sensor graph spends most of its time above 0.5 V, as it should if the converter is working. Update: I started getting this error code again, a little over a year after replacing the cat. I also finally found a guide on how to read these graphs, from ...


7

I think you may have mistaken a service interval indicator for a check engine light. Modern cars will ask to be serviced at regular intervals, even if no fault exists. There indicators can usually be reset the but procedure is usually manufacturer specific. A check engine light is something else and generally indicates that a fault has been logged by the ...


6

I was able to find the exact verbiage on Amazon for a Toyota gas cap. It implies that you will get a CEL (check engine light) and you could, which could cost you money to get it checked out. Here is the listing: Genuine Toyota (77300-33070) Fuel Tank Cap Assembly by Toyota Genuine OEM Toyota Gas Cap New in Original Packaging with Seal. The typical ...


6

The fact that you can smell fuel in the exhaust is a strong indication that the engine is running rich. This means that there is more fuel than required by the engine. There are many things which could cause this and the sensible course of action would involve hooking the engine computer to a scan tool to retrieve data about fuel trims, and O2 sensor ...


5

First guess, bad spark plug wires. You can check by first, doing a visual inspection of the wires, looking for burn spots, particularly if the wire was touching/rubbing on something. Second, on a dry night, crank the engine and lightly mist the wires with a spray bottle of water. You will be looking for a spark to ground and you may also hear it. Beyond ...


5

I've diagnosed this condition many times with a vehicle-specific scan tool, and I don't think it can be done without this or an oscilloscope. O2 sensors work in the range of less than 1 volt (.2v to .7v) In particular, the rear O2 sensor should stay at a fairly constant .5v if the cat is working right. Wild swings to the extremes indicate the cat isn't ...


5

I found a site called actron.com that describes OBDII codes. Autozone explains what the camshaft position sensor is. Camshaft Position Sensor Actuator Operation The Camshaft Position (CMP) actuator is attached to each camshaft and is hydraulically operated in order to change the angle of the camshaft relative to Crankshaft Position ...


5

The Engine System Service Required is a service interval indicator. The engine check light coming on will mean you have a fault. You can simply re-set the Engine System Service Required by carrying out a simply re-set. Button A is located at the bottom and to the left of your speedo. Ensure all doors are closed, Turn the ignition key to position ...


5

Does it make the most sense to replace an old car's entire exhaust system all at once? Considering your car is almost 10 years old, having to replace all of the parts in the exhaust system does not sound unreasonable, especially if your locality uses any type of road solvent during the winter months (they didn't in Montana where I'm from originally, ...


5

Camshaft position sensors are usually Hall sensors, which translate changes in magnetic field to changes in voltage. As far as proximity is concerned, this should be taken care of by the shape and design of the sensor more than the correct tightening torque. By appropriately torqueing down the sensor you are ensuring that it doesn't get loose during ...


5

Turns out this particular issue wasn't due to me running the car out of battery (I believe) but actually to a blown fuse. I guess I had previously left the OBD II plugged in for awhile and apparently if anything else "on that circuit" is turned on it can blow the fuse, and my kids may have turned something on and voila, fuse blown. Another effect of having ...


5

How do I pull error codes from my Kawasaki motorcycle? Here are the instructions to pull error codes from your 2001 or later Kawasaki street motorcycle. Step 1 Pull off your seat and near the battery negative terminal there will be a self diagnosis lead coming out of a connector. The wire is yellow. It looks like this. Step 2 Get a wire, one with ...


5

Because it's dangerous with erroneous data This is actually very smart on Subaru's part. I have to give them credit. If you have sensors that are faulting you could be giving an ECE false or eroneous information. The ECU would then take that false data and make adjustments to traction control and engine power. You could be on a wet or icy surface, step ...


4

There's no immediate way to just know what's wrong, what you need to do is take the car to an advance auto or autozone and have them hook up and ODB-II code reader. They will tell you what code is coming up and can clear the code for you if you'd like. This is a free service, and they will often be able to recommend parts or service based on the CEL reading. ...


4

I don't think it's got anything to do with the timing belt change interval, but the only way to find out is to hook up the car to an appropriate code reader to find out what code is triggering the check engine light.


4

It's just in front of the front passenger side door, under the dashboard. It might be stuck down behind the carpet a ways.


4

This blog is a nice reference: http://check-engine-light-codes.blogspot.com/2006/04/chrysler-1985-95-obd1-code-self.html It explains how to check: Within a period of 5 seconds, cycle the ignition keyON-OFF-ON-OFF-ON. Count the number of time the MIL (check engine lamp)on the instrument panel flashes on and off. The number of flashes ...


4

This can be caused by a number of things, including: Leak in the fuel tank (loose cap) Leaking evaporator canister (plastic housing in engine compartment or under vehicle, also known as charcoal canister) Plugged evaporator canister - there is a tube that is open to the air that can become plugged Malfunctioning purge valve - valve itself is faulty or ...


4

The ECU may have "tuned" itself to the gap and behavior of the old plugs. When you had the plugs replaced, if the shop did not disconnect the battery (and even if they did, not sure about your Ford) the ECU would still have the long term fuel trims that matched your old plugs in effect. So this may result in a bit less or more fuel being injected and ...


4

With some variation based on model year and country of use most faults will latch and self clear. By latching the fault, it is stored and in some cases the "check engine light" also referred to as the MIL (malfunction indicator light) will remain lit after repair until certain conditions are met. The conditions for the fault to clear may involve a certain ...


4

This should not cause you an issue, but this sounds more like a problem with the O2 sensors than with the intake gaskets. When was the last time you had them changed? If you are over 100k miles without new ones, I'd highly suggest this first. One way to check your theory for the intake gasket is by using a spray bottle with water (on jet, not spray). With ...


4

This is normal behavior - When the engine is not running, there is no oil pressure, so when the ignition is turned on, that light will be on. As Larry says, this functions as a bulb test so that you know that it is working. When you start the engine, the oil is pumped round, the pressure goes up and the light goes out.


4

It sounds to me like you mechanic friends are correct. From your description, the car was driven too long on low oil and is now suffering the effects. If you have topped the oil off and are still having the knocking sounds, it's more than likely the engine has damaged bearings with a classic rod knock to tell you about it. With a rod knock, it is only a ...


4

As this article points out, the ability to blink codes was available with older OBD-I vehicles. Once the OBD-II standard hit, the ability to "blink" out codes was lost. This changeover to ODB-II happened in 1996 for vehicles sold in the US. I know the same is true for Volkswagen cars. Early models had the ability to blink out the codes when something was ...


3

I wouldn't risk it. If the water pump fails you can easily cook the engine, leading to no end of problems (failed head gasket, warped head, etc). The temperature gauge will only give you an accurate reading if the coolant is flowing through the engine - if it isn't you will end up with hot spots very quickly. A lot of modern cars have an ecu-controlled ...



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