1994 Ford Probe Check Engine Light-No codes coming through

Engine Mechanical problem
1994 Ford Probe 4 cyl Two Wheel Drive Manual 113K miles

Hi!
My '94 Probe recently has had the Check Engline light coming very regularly.

It comes on about 5-10 minutes into driving, but not consistently. I may drive for 20 minutes, stop for a few, then drive 20 more minutes, and no light. Or, it'll come on after 5 minutes and stay on for 5 minutes. Then it goes off.

I detect no change in car performance, no change in temperature or anything.

Altho--the last 2 times I drove it, there were a few times it felt like it wasn't 'grabbing, ' but I couldn't tell if it was the engine, or almost-bald tires on wet road. (I am not paying the money for new tires & alignment if the car is on its way out)

I took it into the garage. The little computer-plug in (garage realized it needed a Mazda plug-in, and used it) gave no info on why. Don't know why.

He suggested the problem was my oil pressure, and said to trade the car in, soon, before the engine goes.

Are things really this drastic? My oil pressure gauge does ride VERY low, like to the line at times, but it has always done that (Admittedly, I haven't watched it that closely over the 14 yrs I've had it, but I have noticed it was always low).

I also notice that when the tach's go up, so does the oil pressure gauge.

Yet. Sometimes the Check Engline light comes on when the oil pressure gauge isn't all that low. There's been times when the gauge is right on top of the line, and the light still doesn't come on.

Any ideas? It's be very difficult for us to afford a new car just now. But, I have a 4 y.O, and don't want us sitting on the side of the highway someday.

Thanks!
Kris