What are associated "Check Engine Light" problems?

dcdude · 09-04-2004, 06:58 AM

Last night I was driving in to town along the freeway and the cars up ahead were stopping short and when I took my foot off the gas, for no apparent reason at all, my Check Engine light came on.

We pulled in to a rest area to see if any obvious problems were wrong with it, but didn't really see anything.

The hard part is I have the old style gauges that only shows little lights for oil pressure, temp, etc. So i can't really tell if anything is wrong.

The Jeep drives fine and I really would never know anything was wrong with it other than that light

Anyone have any suggestions?

russkrs · 09-04-2004, 09:28 AM

It could be hundrends of things, so hook it up to a comp and get the codes.

joshbish · 09-04-2004, 09:36 AM

Quote:

Originally Posted by dcdude

Last night I was driving in to town along the freeway and the cars up ahead were stopping short and when I took my foot off the gas, for no apparent reason at all, my Check Engine light came on.

We pulled in to a rest area to see if any obvious problems were wrong with it, but didn't really see anything.

The hard part is I have the old style gauges that only shows little lights for oil pressure, temp, etc. So i can't really tell if anything is wrong.

The Jeep drives fine and I really would never know anything was wrong with it other than that light

Anyone have any suggestions?

I'm not sure what year you have, or if it matters --- i am able to do this on my 93 and my 97: Buy a Haynes manual, it will have the majority of the most common codes in their. Then get in your car and turn the key to the on position (the position right before it turns over) 3 times in a row --- but on the 3rd time hold it there. If you have a 97+ with the digital mileage gauge, then the code numbers will show up on there. If you have a pre97 then you will need to count the number of times the check engine light flashes. A lot of times it starts with 12 --- this has something to do with the battery being disconnected recently --- ignore it. The code numbers will always be 2 digit numbers and the longer pauses separate the codes. It will always end in 55 --- this just means it's done. Hope this helps. Good luck.

russkrs · 09-04-2004, 09:41 AM

I can never get that to work in my 98.

dcdude · 09-04-2004, 10:26 AM

OK, well I tried the turn it to on position 3 times thing and it DIDN'T show any codes but the weird thing is the check engine light turned off after the third time!

So I'm guessing it's fixed and there was nothing wrong, thanks a lot man.

And yeah I do have one of those Haynes manuals but I left it at home in Florida and I came up to virginia for the weekend so I don't have it with me.

Thansk again

fourlow · 09-04-2004, 01:30 PM

If it drives fine and the light comes on, it could be the o2 censor. Atleast it was on mine.

BrunoS · 09-04-2004, 02:07 PM

usually in higher mileage vehicles a lazy 0xygen sensor causes this problem, after driving on freeway, and then suddenly idling, the computer doesn't see that exhaust change as fast as it should...and thus sets a trouble code. try a bottle of CD2 emission cure (cleans 02 sensors and catalytic converters), in the gas tank for a few miles, coulda got a tough batch of gas that got some -=-=-=-=-=-=-=-= stuck to the sensor...but if it went out, then you probably burned it away. I wouldn't spend any money on it beyond that, always pull codes before tossing more cash on the problem. note that after around 100k, a new o2 sensor for $30 is worth the gas mileage increase....all o2 sensors wear out.

On chryslers, the older ones would blink codes, 55 is the all clear signal....i can post all the codes if you like.

09-04-2004, 09:28 AM	#2
russkrs Registered User Join Date: Feb 2004 Location: New Castle, IN Posts: 1,823 Profile Gallery Classifieds My Jeeps	It could be hundrends of things, so hook it up to a comp and get the codes.

09-04-2004, 09:41 AM	#4
russkrs Registered User Join Date: Feb 2004 Location: New Castle, IN Posts: 1,823 Profile Gallery Classifieds My Jeeps	I can never get that to work in my 98.

09-04-2004, 10:26 AM	#5
dcdude Registered User Join Date: Mar 2004 Posts: 44 Profile Gallery Classifieds My Jeeps	OK, well I tried the turn it to on position 3 times thing and it DIDN'T show any codes but the weird thing is the check engine light turned off after the third time! So I'm guessing it's fixed and there was nothing wrong, thanks a lot man. And yeah I do have one of those Haynes manuals but I left it at home in Florida and I came up to virginia for the weekend so I don't have it with me. Thansk again

09-04-2004, 02:07 PM	#7
BrunoS Registered User Join Date: Aug 2004 Location: South Bay Los Angeles, CA Posts: 2,538 Profile Gallery Classifieds My Jeeps	usually in higher mileage vehicles a lazy 0xygen sensor causes this problem, after driving on freeway, and then suddenly idling, the computer doesn't see that exhaust change as fast as it should...and thus sets a trouble code. try a bottle of CD2 emission cure (cleans 02 sensors and catalytic converters), in the gas tank for a few miles, coulda got a tough batch of gas that got some -=-=-=-=-=-=-=-= stuck to the sensor...but if it went out, then you probably burned it away. I wouldn't spend any money on it beyond that, always pull codes before tossing more cash on the problem. note that after around 100k, a new o2 sensor for $30 is worth the gas mileage increase....all o2 sensors wear out. On chryslers, the older ones would blink codes, 55 is the all clear signal....i can post all the codes if you like.