'95 Neon 'Check Engine' light on

[wastesicoot]

My friend's Neon was towed home last night because the engine overheated on the highway. I checked it out and found a dead radiator fan relay. When I replaced it with the horn relay the radiator fans came on almost immediately. I then noticed the 'check engine' light was on. I'm assuming it is on because the engine had overheated. The car runs fine now and there are no other problems. I asked a mechanic if they could clear the code from the car and was told it would cost about $80 to do it right away, or I could wait a couple of days and the light might go away on its own. My question is: Can I clear the code myself without buying expensive equipment and how? I tried removing the negative battery cable and it's still there.

[boingo82]

Moved to Dodge: Neon.

How long did you leave the battery disconnected? Some cars it takes overnight to reset the ecu. I don't know that the Check Engine light would be on just from overheating - usually it means failure of an emissions/fuel system part such as o2 sensor, etc. And what happens now if he needs to honk?? I'd go to a junkyard and get a replacement relay if I were you.

[mattzneon]

Hey homie...
Autozone has a computer they can run on your car for free and it'll give you a code and they can reset your ecu with theirs. Most autozones have this. The code will tell you which type of sensor is at fault, but not which one. Like, it'll spit out a code sayin' you've an oxygen sensor that is out, but do you actually know how many of them you have... and where they are at... Exactly. That $80 will tell you exactly which one it is, and they can do all that computer stuff. You can go get the code from AZ and if it is remotely close to one of the problems you just fixed, maybe the computer just needs a resetin'. I know SOME CARS can reset the ecu by puttin' the key in 'on' and 'off' 3 times consecutively. Never tried it on my Neon, but I know my brother's '91 'stang it worked. Try it. I'm no mechanic, but I'll fill you in on everythin' I know on the subject.

Matt

P.S.
By the way, my SE light is on also... Its my EGR valve. No major prob other than bad fuel economy, but it'll stay on for roughly 2 weeks then turn off for a few weeks. LoL! I just dont wanna spit out $75 for the solonoid. lol! I just consider the bright yellow light cosmetically delightful.

[dnkygirl]

Originally posted by mattzneon
Hey homie...
Autozone has a computer they can run on your car for free and it'll give you a code and they can reset your ecu with theirs. Most autozones have this. The code will tell you which type of sensor is at fault, but not which one. Like, it'll spit out a code sayin' you've an oxygen sensor that is out, but do you actually know how many of them you have... and where they are at... Exactly. That $80 will tell you exactly which one it is, and they can do all that computer stuff. You can go get the code from AZ and if it is remotely close to one of the problems you just fixed, maybe the computer just needs a resetin'. I know SOME CARS can reset the ecu by puttin' the key in 'on' and 'off' 3 times consecutively. Never tried it on my Neon, but I know my brother's '91 'stang it worked. Try it. I'm no mechanic, but I'll fill you in on everythin' I know on the subject.

Matt

P.S.
By the way, my SE light is on also... Its my EGR valve. No major prob other than bad fuel economy, but it'll stay on for roughly 2 weeks then turn off for a few weeks. LoL! I just dont wanna spit out $75 for the solonoid. lol! I just consider the bright yellow light cosmetically delightful.

Resetting is easy disconnect the positive cable not the negative... for about 5 minutes. Make sure you do get the code first before you clear it. Also EGR is a real pain in the butt Mdawg the longer you let it go on like that the worse your gas milage gets... i know from experience. I just replaced my egr valve and the sensor and now my gas milage is back to normal. I was filling up every other day at about 120 which is crazy... It also made the engine idle really hard... which scared me...

[mattzneon]

hahaha!
sorry typing will be really sloppy bcuz iv an apple in mt other hand lol

exacty tho! my idle gets bad sometimes also!!! scurrs me 2! yeagh gas clocked in @ 21 yeste5rday.... it is much worsse than my 27mpg i used 2 get..... and i think u r right on that.... it appears 2 b gettin worse which sucks! not at a quik rate however. i'm sure i'll be down 2 lyke 11 b4 i kno it!lol hey, did u chang urs on ur own? how much did u pay for 'em both? is thtere any performance upgrades eligible in that area? instead of stock i would buy upgrade.... but i dun think there is any...



m.homie

[dnkygirl]

I changed it myself... please don't pay to have this done.. it's easy, but requires you to dislocate your hand a little... he..he.. the bottom bolt is really hard to get to so i was almost laying on top of the engine to take it off. No there's no performance upgrade available.. actually you can completely remove the crap from your car and not have it affect anything, but the problem is the pcm. It will always be on.. unless you buy a new pcm that over looks that area. Another issue with removing it is emissions test.... some states require it be on the car and will visually inspect under the hood for it... yeah... you can buy a block off kit from mopar or vitors... and keep the piping in place...

Those new pcms are expensive and i have an ATX so it's not even worth it for me to do that. Buying a new EGR valve which comes with the sensor... which is really the problem to begin with... cost me 92 bucks. Once that sensor goes bad it will leave the valve in an open position which is why your gas milage is sucking. It's also time to clean the intake... you might want to get some intake cleaner... after running with the egr open like that for some reason my intake is really nasty... alot of carbon build up...

[mattzneon]

damn dnky! thats right on the money right derr! I talked to a tech and he said the exact same thing! So I'ma change it out. I was goin' to do myself, but just wanted to know the difficulty level. If you take it out completely, do you still get bad mpg and rough idle?


m.bezzle

[dnkygirl]

If you take it out no the idle will stop and gas milage will improve... but your check engine light will remain on .. i just have issues with that myself what if something else is happening you won't know cause it's always on. Hey can you pass emissions with the check engine light on? not sure....

[mattzneon]

I'm sure you can. If you have the connections lyke I do, you just have a friend write you off an inspection. I think you can though. I mean, somethin' might seriously be bad... Lyke homeboys boy that started this thread. His light came on because of the fan relay switch. That has nothin' to do with emissions. I mean, the light is not just based on the emissions... right? If the fan turned it on... Right? Well I'm off to go get my valve now. Lol. Have me itchin' for a new. Lol! Thanks shawty!


M.beeezy

[dnkygirl]

No that check engine light is connected to the pcm anytime there's a sensor or relay failure is when it comes on... so riding with your light on is not a good thing... you really need to check the codes to see what's causing it to come on... here's a link to the list of codes for the neon:

Check Engine Codes List

[mattzneon]

dnkygirl... mutha fucka! lol! excuse the language on the board... I just changed out my EGR valve... Sure, its somethin' simple... If you can even get to half of the bolts! That thing is not made for human hands! My hand is all cut up from diggin' in there! LoL! Luckily my brother is an aviation mechanic and has every tool designed. LoL! We used a ratchet/boxend. Shyt worked great! Well, when we finally utilized it. I too was laying on top my engine! Hahhaha! Yeah, my light didnt go off right away, so I took it to autozone and had them turn it off. I got my valve for $75. What all did you change on yours? I bought the EGR valve and it came with the aluminum piece that bolts onto the block and the plastic piece (with tubes) that mounts to the intake. Am I right... Is that the solonoid on that plastic piece? Because there were two attachments to it, I dont know what they do. Also, you changed your sensor, can you tell me which part that is? I'll take a pic with the digi cam soon so you can show me. Thanks tho!

Mdot

[DEMON1]

Glad to know auto zone is there to lend a hand!! I work in an auto parts store in NY and I always send my customers to autozone when they have a diagnostic problem!! Hey it's the cheapest way!! Then they come back and buy the part from me!!

[daytonaes93]

be careful w/ that check engine light it might fool u.
my parents have a 97 breeze and the light is stuck on.
autozone couldnt get a code on it, could even clear it either
even tried clearin it w/ a 4000 dollar snap on computer.
still nothin
might have to replace the computer. i know of a lot and i mean a lot of people with new chrysler products w/ engine light problems.
u might get lucky though
just though id put in my info

[dnkygirl]

Originally posted by mattzneon
dnkygirl... mutha fucka! lol! excuse the language on the board... I just changed out my EGR valve... Sure, its somethin' simple... If you can even get to half of the bolts! That thing is not made for human hands! My hand is all cut up from diggin' in there! LoL! Luckily my brother is an aviation mechanic and has every tool designed. LoL! We used a ratchet/boxend. Shyt worked great! Well, when we finally utilized it. I too was laying on top my engine! Hahhaha! Yeah, my light didnt go off right away, so I took it to autozone and had them turn it off. I got my valve for $75. What all did you change on yours? I bought the EGR valve and it came with the aluminum piece that bolts onto the block and the plastic piece (with tubes) that mounts to the intake. Am I right... Is that the solonoid on that plastic piece? Because there were two attachments to it, I dont know what they do. Also, you changed your sensor, can you tell me which part that is? I'll take a pic with the digi cam soon so you can show me. Thanks tho!

Mdot

I changed the solenoid and the pcm which is the plastic thing it attaches to with those valve tubes. he..he.. i feel ya on the hand disconnecting!!! I disconnected mine too... the hardest part was getting that bottom bolt back on. Yes i forgot to tell you that you have to clear the code after you install the part because it won't clear itself. Now your gas mileage should return and that noisy growl when it's cold should go away. Sounded like the engine had cramps... i can associate with that... he..he...

[boingo82]

Originally posted by daytonaes93
be careful w/ that check engine light it might fool u.
my parents have a 97 breeze and the light is stuck on.
autozone couldnt get a code on it, could even clear it either
even tried clearin it w/ a 4000 dollar snap on computer.
still nothin
might have to replace the computer. i know of a lot and i mean a lot of people with new chrysler products w/ engine light problems.
u might get lucky though
just though id put in my info

Same thing on my parents' 98 Caravan. Light's been on for 45,000 miles, dealer can't find any problems.