service engine soon light

I have a 98 S-10 4.3 and the servce engine soon light just started coming on .has anyone encounted this before? could it be the o2 sensors? does anyone know how many there is and is there anyway of testing this?:smoka:

when my truck got up to the 160 mark the light came on but when i passed it up it went away so if you have high miles it is programmed into the truck...dont worry about it

80% of the time, the Check Engine Light goes on when there's a trouble with the emission system.

Check your O2 sensors, air/fuel/oil filters, etc.
Basically, do a routine check for starters if you haven't noticed anything weird on your truck's running condition.

when my truck got up to the 160 mark the light came on but when i passed it up it went away so if you have high miles it is programmed into the truck...dont worry about it


no, its not programmed to come on at a certain mileage.

Take it to autozone, they will scan your ecm for free and tell you what code is there and what it means(there are oover 500 codes that will set off the SES light)

i know this sounds stupid, but i left my gas cap at the service station, and the service light came on, it can be really simple stuff that sets it off, go to autozone, and you'll probably get a p404 error (emissions code) the codes are generally VERY vauge, so you'll have to look at a dozen different things. just keep in mind, don't overlook the simple stuff.

not sure if this will still help?? the chiltons manual for my 91' only goes to 92', so i am not sure if the emmisions control system has changed so dont try anything till you get a book and find out!!!. but on my year you can short terminals in the plug under the dash that will put you ecm in the diagnostic mode. the check engine light will flash you codes to tell you what cause the light to come on and store a code in the first place. once you have the code look in the manual. its probally would be quicker to take it autozone and let them play with it, but i like to do me playing myself...
one quick question to the rest of the forum, does this still work on the newer models like this one?

Sorry to jump in here guys but the terminals Slappy was talking about are the A and B terminals in the diagnosic conector ( Usually located under the steering column way down low on the dash). Just wanted to clarify for any that may not know what Slappy meant.