need help not mc related

[oldgoat]

i was out driving my 2005 pontiac grand prix 74.000 miles on it i was down to a 1/4 tank of gas then the check engine light came on? this has done this before in may on my trip to MN but after a fresh tank of premium gas it went off? and has not come back on untill now when i went and put a half a tank of gas in 2 days ago and ran it down to the 1/4 of a tank. this was regular gas not premium? im hoping that now that i filled it with premium it will go off again after running this tank out? any ideas what could be the cause of this? i just cant afford a major problem right now. i dont feel any loss of power?

thanks oldgoat

[lshafer]

Maybe your gas cap wasn't on tight. I've had that happen before and when I stopped to fill up I obviously tighter the cap and bam, lights out!! Just a thought.

[Keemez]

Maybe your gas cap wasn't on tight. I've had that happen before and when I stopped to fill up I obviously tighter the cap and bam, lights out!! Just a thought.

 

X2

 

Also, why are you wasting $ getting premium gas?

 

Adding to FF's suggestion below, I suspect you'll have a P0440 (EVAP system leak) if the gas cap was indeed loose.

Edited January 22, 2012 by Keemez

[Flyinfool]

Go to an AutoZone and they will check the code for free.

That will at least let you know what the engine is complaining about.

If the check engine light is flashing, it is something serious and should be dealt with immediately. If the light is on steady it is usually something minor.

 

We could all sit here and guess at stuff all day long. Go get it checked for free and let us know what the code is.

 

+1 more, don't wast your money on premium gas. Premium will not fix anything.

[oldgoat]

its on steady? as for premium gas. i bought the car brand new in 2005 and the manual said run premium? i kind of thought that was a mistake and .15 more a gallon does not help cash flow. i will go and see if i can get a code check as see where where at. im looking at the manual and it couls be anything from bad gas to a bad gas cap to a air filter? or fuel filter i realy dont need this problem. just cant understand whay gas would do it? but like i said it happend before and a fresh tank of gas and 400 mile run it cleared up. but now that i dont go out much a tank of gas last me 2 weeks and im not ready for a 400 mile trip:no-no-no: i think and pray it will be a minor thing.

[kevin-vic-b.c.]

replace the gas cap, pour a can of seafoam in it and it will be happy I bet..... But ..... if you are able to get the code read for free go get it done. Here we still have to pay to have the code read.

[wizard]

The check engine light indicates there is something involving your emissions system. Check the codes with a scanner, go to most any parts store and they will check it for free. They will lead you in the right direction. My Ford, a 96, has the light on, when I need to get it smogged, I will clear the codes, run the car for a few miles, just long enough to clear the light before it reaches the last couple of codes and get it tested. I believe that I can pass with 8 or 9 codes and still pass. Don't worry about it otherwise. The car will be ok and run fine with the light on.

[Flyinfool]

If the owners manual says to run premium then you may have an engine option that needs it.

Usually if premium is required it will also say so on either the gas gauge or gas cap.

 

First thing is get the code read, write down what it is, and then have them clear the code. Maybe it will stay gone.

[bongobobny]

Yah! If the code indicates massive evaporative leak try a new gas cap on it and make sure that the neck of the filler tube isn't corroded or rusty causing an air leak. Other problems can be the canister, the sensor on the gas tank, or a corroded connector for the sensor.

 

Depending on which engine you have it may very well require premium gas, especially if it is a turbocharged version. That was the main reason when I bought my 2005 Monte Carlo I did NOT buy the SS version as it required premium gas as opposed to the 3.8 liter which runs on regular...

[bongobobny]

PS if the light is on steady it just means a code was detected, and needs service in the near future. If the light is flashing it is more urgent and requires immediate attention...

[KIC]

You can also disconnect the battery and then reconnect it. The light should go off . If you have a problem the light will come back on. I also agree on the free code reading at Oriellys or Autozone

[MikeWa]

Your engine system has a knock sensor in it. You can run regular fuel but performance may suffer a little. The check engine light may reset itself after three to nine drive cycles if the problem was only momentary. Or it may not reset indicating a continuing problem. Get it scanned. Get the codes and decide from there what action to take. O2 sensors have a life cycle as do gas caps. Throttle position sensors can wear out. And other things can just fail. Don't guess. Get the codes. Then decide.

Mike

[darthandy]

Here's something I ran across a few years ago regarding Corvettes, but it could apply here. As you know, most, if not all, gas caps have a "ratchetting" feature when you tighten them. Some people with Corvettes were getting check engine lights that were traced bac to the fuel caps not being tight enough. It turns out that they had to give the cap two or three good turns to make sure they were tight enough, even though they "ratchet" at the end. Not too likely, but it doesn't cost anything to check. But as others have said, get the codes read - that will be the best place to start.

[CaptainJoe]

I agree about having the codes checked ... but

 

Anytime you have a check engine light immediately check your oil level and anti-freeze

as these are the two things that can seize you engine up....

 

If I had to GUESS.... Its either a loose defective gas cap, You got bad gas I noticed your from IL... put a can of dry gas in, a bad oxygen sensor, or even something as simple an indication that you need to change your oil?

[MiCarl]

As has been implied here, once the light comes on it will stay on for awhile even if the problem goes away or is corrected. It can be reset with a code reader or by disconnecting the battery, but will reset itself after a certain number of starts without the fault recurring.

 

You need to get the code(s) read to know what is going on.

 

The service engine light on my 1997 Yukon with 180,000 miles came on. I was surprised when I read the codes that it was not an oxygen sensor preheater, since those commonly wear out. Instead it's a low voltage condition in the O2 sensor circuit. Could be a problem with the ECM - lots of $$.

 

It runs like a scalded cat and gets 17mpg highway. I've opted to ignore the light. You would think the darn bulb would burn out in 25,000 miles though.

[Freebird]

Tightening the gas cap until it clicks is important. I had a LOT of customers come in a few years ago when I worked for a local Chevrolet/Olds dealership. On newer cars, the problem 99% of the time was that they were not tightening the gas cap until it started clicking. I always turning it until it clicked a few times, maybe another 1/4 turn or so just to be sure.

 

Now last winter my company car, a 2007 Dodge Caravan, had the check engine light on. It went off a couple of times but stayed on most of the time through the winter. When spring came and it warmed up outside, it went off and has not come on since. I don't know if it had anything to do with winter or if it was just a coincidence that it cleared up. I thought at the time that it may have had something to do with the re-formulated winter gas but I don't know. I never did get the codes read.

[oldgoat]

well i give up. i made an appointment to have it checked out. i head down to the shop about 4 miles away. the lights on all the way. i made the left hand turn into the shops driveway and bam the light goes off? of course the scanner wont show nothing now?

so he kept the car gave me a ride to my brother in- laws house because my brother-in law was kind enough to borrow me his spare truck. and the mechanic said he will check and see why its doing this. where thinking a connector is getting wet ? and when it dries off the light goes off?