1993 Saturn SL2 stalling engine

1993 Saturn SL2 stalling engine
Re: "Our 1993 Saturn SL2 engine stalls when under load. Initially, when I asked for help here I was told to check several components including the spark plugs. This problem has been occurring for the past few weeks with increasing frequency. Our engine is the 1.9 litre twin cam engine. The vehicle has 119,000 Kilometres or 74,375 miles. The service engine soon light does not come on. It is in working condition. I checked this when the engine is off and the ignition is on the service engine soon light comes on. Then we replaced the four spark plugs with new ones with platinum tips. The result was phenomenal. It performed like a new engine. However, two weeks later the same symptoms came back as if the old spark plugs were installed instead of the new ones. Please note that the old spark plug in cyl. #4 was wet with oil and gas before the new one was installed two weeks ago. Please, I need someone to tell me what needs to be done. Thank you.