The engine light came on the other day while accelerating, soo when i got home i shut it off and waited awhile and started it again and it was still on. I then took off the neg. battery cable and left it off for about 5min. Put it back on and it stayed off for the rest of the day and then came back on at the end of the day. Does anyone know what it could be before i bring it in?

 

check your gas cap...this can cause the light if it is not properly fastened. i would say check for a code through your digital tach...but when i did it i got a code for oil pressure switch. it turned out to be something else. that light can mean a multitude of things i learned, but the gas gap should be the first thing to check. oh ya, i think it can also be caused by crappy tank of gas...you fill up lately? check your manuel, it tells you for sure, but i believe crappy gas can cause this. not sure though. good luck.

 

How many miles on it?

If it's over 55K I have seen an O2 sensor display these symptoms. The code will help but in my case my O2 sensor would only set a check engine light under accleration, over 60 M.P.H. in the heat.

Go figure.

The code said something irrelavant to the failure.

They recommend O2 sensor change outs like tune-ups intervals.

That was my first O2 sensor caused "check engine" light.

 

the digital tach trick dosent tell you anything about the check engine light, it just diagnoses instrument cluster problems.

you need to get an obd-ii scan tool - they are like $150, but autozone will let you borrow one for free and scan the codes. they should be able to tell you what they mean. if your truck is still running ok its probably some emissions crap and not a big deal, but you should get it checked out...

 

When was the last time you changed your spark plugs ?
If you have old plugs and a piston misfires, it will trigger the check engine light.
I had this happen to me recently !

 

I HAD THE CHECK ENGINE LIGHT ON FOR THE LAST 15K MILES. I HAVE 99K MILES RIGHT NOW. I HAVENT BEEN ABLE TO GET IT CHECKED BUT AFTER A WHILE I JUST FORGOT ABOUT IT. A MECHANIC CHECKED IT OUT AND TOLD ME THAT HE COULD NOT FIND ANYTHING WRONG AND THAT I SHOULD JUST KEEP ON DRIVING IF THERE IS NOTHING WRONG. IAM SURPRISED HE DIDNT TELL ME THAT MY ENGINE WAS IN NEED OF REPLACEMENT.

Sorry about the caps.

 

jrm1493,

Do you know where to get the OBD-ii scan tool at? I asked Autozone and they said they didn't have any, in stock or special ordered. I have tried around the net for a little bit but I had no luck.

 

Here Ive found a few. They are kind of high in price. One is here

Click Here for $299

Click Here for $359

Click Here for $349

HOPE THAT HELPS

 

in 17,400 miles my check engine light has come on. To remedy, I have now had a DPFE sensor replaced twice by the dealer. The first was around 11,000 and now the second time was friday at 17,400. I am wondering if my mods have caused this.

2001 4.2l XL 2WD SB
5-Speed
3.55 axle

Mods:
Gibson Super Truck
AirRaid FIPK
Rhino Liner

 

i live in north austin, and the autozone by my house (on Lamar just south of breaker lane) is not only open 24 hours, they have an obd-ii tool for rent and one for sale! its a sweet store and when i broke an intake bolt off in my friend's 302 cylinder head i was glad they were open at 3 am!!!

 

the one they have is only $150 but all it does is read codes and i dont think it does any realtime diagnostics like some of them do...

 

also longhorn hoss,

the one they have is only $150 but all it does is read codes and i dont think it does any realtime diagnostics like some of them do...

what does your truck look like, i've probably seen you around campus (i'm in grad school at UT and a texas ex). my truck is silver (bone stock) with a CCA sticker and another yellow sticker on the rear window. if you see me around holler at me...

 

9 out of 10 times its an egr pressure sensor or egr electronic valve problem...

 

If I had to bet money on it, I'd say it was your DPFE. They get contaminated with water a lot and that ruins them. If you dont know what a DPFE is, find you the EGR tube that goes from the exhaust manifold to the EGR valve and find the two rubber hoses attached to that tube. Follow the hoses to the DPFE. ITs a rectangular lookin thing with one electrical connector and has the two rubber hoses connected to the bottom of it. Its fastened on with two 7mm bolts. Remove that and tap it off your hand as if you are trying to get water out of the two ports that the rubber hoses connect to. If you get water from the holes, the replace it and disconnect your battery as you did before. However DPFE's do go bad sometimes even without water getting in them....................When ya put the DPFE back on, make sure you connect the rubber hose to the rights ports on the sensor. If ya dont, that will cause another problem............Hope that helps ya a little

 

Has anyone found that the fuel filter may be the issue of the check-engine warning light, say . . . around the 45K mark? When my light came on I had been noticing a bit of surging while driving, which may meam plugs, filter, O2 sensor, and related. And did anyone try a fuel treatment fix? I know that the light may go out after 3 extended on/off periods, but I continue to receive surging issues.

Thanks all -

Mike - darkcompass@hotmail.com