1999 dakota - check engine light.

Do you know why it illuminated in the first place?

Disconnect the battery for 15 minutes.

But why did it come on in the first place?

it was running rough. is there a way to check codes , i.e. have the engine light flash?

Unfortunately no, not on a '99. You need to get an OBD-II scan tool to retrieve the codes.

Many auto-parts stores will let you use theirs in the hopes of selling you some parts.

On that same note, will a OBD-II scan tool tell you which sensor tripped the check engine light ? IOW, I have a 99 Dak also, and never had to change a sensor, but I know I'm running on borrowed time at this point. If I have a sensor go bad, how can I figure out the bad sensor ? Will the code tell me ? I'm pretty sure I have 2 02 sensor's. Does the code get specific enough to tell me which one is causing the fault?

Yes it does.

"TBone" wrote in news:Sx4Pe.36261$es2.574453 @twister.southeast.rr.com:

Cool, thanks.

Just understand that the scan tool isn't always right. More to the point, just because it says there's a problem with xxx sensor, doesn't mean that xxx sensor is bad. Case in point: a friend of mine had a CE light on, scanned it, and saw that the O2 sensor (pre-cat) was reporting lean. He replaced the sensor, cleared the code, and within minutes, the code was back.

When we actually looked the engine over, we found the intake manifold gasket was leaking, allowing more air in than the MAF was reporting, and causing a lean condition. The O2 sensor was working perfectly - the mixture WAS too lean. He thought he could fix the problem in 10 minutes with an $80 part. As it turned out, it only cost about $20, but about three hours, to do the job right. Needless to say, he didn't get his $80 back, and after buying lunch and beer, was out even more cash :)

"Tom Lawrence" wrote in news:POsPe.2012$ snipped-for-privacy@newsread1.news.atl.earthlink.net:

Excellent point. Always best to dot all your i's and cross your t's before swapping parts.

Again, thanks