What is the most common causes of the infamos "check engine light" I have a 91 eclipse and it comes on and off all the time but everything seems normal. Sometimes on highway driving it is mostly off. but stop and go it is usually on.

 

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Well, this probably isn't your problem but here's what happened to me. One day I got gas and I guess when I screwed my gas cap on the security wire that keeps the cap from getting lost got caught in between the cap and tank when i screwed it back on.</P>


So basically my cap wasn't closed all the way, my check engine light came on and just went off finally about 5 days ago. It was on for over 3 months!! So not tightening your gas cap all the way might do it.</P>

 

yeah the mitsubish engine is designed to do check every so often and if somthing if off like your gas cap, or coolant levels then it will turn the light on and stay on again until the car does its check again, and if the problem is gone the light is gone.

 

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There are a lot of reasons why your check engine light would come on, but the most common reason is gas/air ratio. That narrows down your problems a little bit, but not really by much. It could be anything from a loose gas cap (which will cause excess amounts of air to flow in) to a hole in your flexpipe (which will cause excess amounts of air to flow in from underneath) to just a busted solenoid (which will just cause a misreading by your ecu). So it really could be any number of things. Just take it to a mechanic and have them run a quick check. It'll probably cost you about half an hour of labor for them to hook up the computer and diagnose your specific problem.</P>

 

<IMG src=smileys/smiley19.gif border="0">i went to get my check engine light checked, and it turned out to be my head gasket was leaking anti freeze into y bock with totaly ruined half of my engine so 2000.00 in new parts and labor, my car is running again... woot<IMG src=smileys/smiley4.gif border="0">

 

<FONT face="Arial, Helvetica, sans-serif" color=black size=4>This might help as has happened to me. I had pulled the air filter housing apart to change filter and while doing so, accidentally pulled off a temp. fuel spade connection. Sensor was located in thermostat housing.When off, light was on and ran like heck.Found the knocked off wire and Bingo, light off and ran fine. Hope this helped </FONT>

 

there could be Alot of reasons why your CEL would flash on, take it to a checkers or some place that has a scanner and pull up the code and look it up, it could be bad or it could be the littlest thing, for example a O2 sensor. peace

 

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I just changed an engine out. This engine has 12,000 mile on it - looks and runs like new. That stinkin' idiot light keeps coming on and yet runs great. I reset it by cutting the DC. It varies, but after a few hundred miles it goes back on. The dealer wants $72 to hook it up to a computer. It is difficult to justify the cost when the thing seems to run fine. Comments?</P>


Thanks.</P></FONT>

 

<IMG src=smileys/smiley17.gif border="0">allright,the old man is gonna help you out here,and it will cost you less than $15 to read your problem code.All first generation eclipses,talons,and lasers up to 1994 can be checked by buying or borrowing an analogue volt meter.That's a volt meter that has a needle as opposed to a digital readout unit.These can be purchased just about anywhere for around $10.Also purchase a couple of cheap alligator mini clips while you're at it.Locate your reader terminal on car,it is attached to the right side of fuse block under the dash just to the left of steering column.It has a black vinyl cover over it.Connect meter to terminals that are at opposite corners from each other using alligator clips(you can't mess this up because one corner does not have a terminal.Set meter to read D.C. volts so you can read 12 volts.Now tturn ignition key to on position but do not start car.Meter will jump to 12 volts for a second and then go into saved trouble codes.The meter will indicate the tens digit first followed by the ones digit second.Tens digit indication lasts for 1.5 seconds and ones digit lasts for half asecond.For example, if meter goes to 12 volts once,then again,then a pause,then 3 quick jumps,this would be problem code 23.You need a chart to tell what this code means,i will fax someone the code chart and directions if you really need it.Also, there may be more than one code stored in computer if you have multiple problems,they will be displayed in numerical order and then they will repeat sequence.If anyone else needs help with first generation problems,I have the full factory service manual on disc(all 1215 pages,whew !!!)and i'll try to help.Stop paying outrageous repair bills and fix the f***ing thing yourself !!!!

 

what i said to the other guy applies to you too, go to a place that you can use a scanner. example ( CHECKERS ) and plug it in your ECM and pull the code out ... save you lots of money that way