my service engine soon came on. I have a 97 or 98 Pontiac Grand Prix. should I be worried it came on before

Question

the oil was chnaged monday, the light came on thursday night.

Answer 1

I wouldn't necessarily panic about it, but it is important to take the time to find out WHY it came on. Take it to a shop and get it dianosed. The problem may affect performance, fuel mileage or any number of things.

Some places (AutoZone, et al) will often do it for free, or for a very reduced price. If not, take it to a shop, getting it diagnosed does not obligate you to get it repaired there, it may be a sensor that you can replace yourself.

Answer 2

Always get a check engine light diagnosed quickly. A large percentage of the time it can be a small problem or even something as simple as a gas cap that is on loose. But other times it can be serious.

Example 1: A coworker with a '99 Bonneville and 3.8L engine had the light come on for a misfire. Turned out the intake had corroded/burnt through by the EGR valve and coolant was being sucked into the engine. It wouldn't have taken much driving and the engine would have been ruined.

Example 2: A roommate and I were leaving for work when the light came on 2 miles from home. We turned around and got a different car to go to work. That night we drove 10 miles to the parts store and it showed a code of low fuel pressure. Two miles later we were calling a tow truck because the fuel pump had completely died.

Many parts stores can run a diagnostic on it for free but they may not know the exact code or reason why. Remember...they are getting paid $6-10 an hour. If they knew that much about a car they could work for a shop and earn more. I used to work at a parts store and was amazed at how much bad advice was given.

Answer 3

I don't know that "worry" is the right term for it...you should be attentive and concerned however. Many auto parts stores will "pull the error code" for you at no cost in the parking lot. A scanning tool produces the exact error code, it's description, and often times what needs to be done to correct it.

Based on the age of the vehicle I would guess it's an O2 sensor that is starting to give out false readings or possible the catalytic converter doing the same. It will take you 10 minutes and cost you nothing to have the code pulled...Autozone is the easiest place to do this. If you don't have one in your area check with other parts stores for the free service.

If it is a common maintenance issue like an O2 sensor you'll want to get it replaced. This is the most overlooked cause for drop in gas mileage, without proper reading froms the exhaust system the ECU doesn't know how to tune air volume, fuel volume, etc properly.

Hope this helps!

Answer 4

also own Grand Prix '98. 1.) how long since last oil change? 2.) may just be oxygen sensor, local parts store, ie: napa should have diagnostic machine to check codes on your engine. takes about 10min. Minimal charge or free at some locations

Answer 5

if it drives the best thing is to play safe and get a diagonistic test run on it, go to a mechanic and get it checked out. maybe you need oil