1990 Toyota Camry surging

My daughter has a Toyota Camry which is a great car. She is having problems with it surging lately and reading the code it said the O2 sensor was malfunctioning. We replaced it and it is running better but now it's surging around 1.000 rpm, the car is bucking and being a pain. Having a GM with the same problem I changed out the throttle position sensor and it helped a bit but it's still doing it. If anybody has an idea what the fix is please let me know. Know my way around GM's but this thing is stumping me!!

What code did you get? Is it still there after cancelling the codes and driving it?

4- or 6-cylinder? Does it start easy when cold and hot? How is it at idle? How is fuel economy?

As Brian stated, having the actual code can help, but because there is a fault doesn't automatically mean that part has failed. It means something is wrong with that circuit...be it a dead sensor, bad wire, poor or loose ground, corrosion, etc. You might recheck the O2 sensor circuit to make sure it isn't broken.

Yes, disconnected the battery for about five minutes after both sensors. The code is still showing up as 25/26 lean fuel mix, rich fuel mix.

Initially we found the wire to the O2 sensor was broke and replaced it, that's when the surging issues started. I checked the O2 sensor which was non-operational and replaced it and tested the Throttle position sensor which was weak and have replaced it as well. It is a 4 cylinder and when it's cold it starts okay but revs high for about 1 minute then comes down on its own. The fuel economy has not been great at all.

Check your fuel line pressure, air flow meter, and coolant temperature sensor. These are most likely....

If I were a betting man, I'd bet it was the coolant temperature sensor.

Check your fuel line pressure, air flow meter, and coolant temperature sensor. These are most likely....

If I were a betting man, I'd bet it was the coolant temperature sensor.

I'll check the temp sensor and find out in the book the fuel line pressures, I have a Gage as I replaced a pump recently.

Hi! I have an 89 Camry that has a surging problem too. Cap, rotor, wires, plugs, fuel & air filters, O2 sensor, H2O pump, and full timing set have all been replaced. A fuel pressure or pump problem have been ruled out because acceleration and heavy fuel demand are fine. Problem occurs only when coasting or decelerating between 25-50 mph. Touch the accelerator or even the brake, and surging stops. (?!)

89toycam

Hi! I have an 89 Camry that has a surging problem too. Cap, rotor, wires, plugs, fuel & air filters, O2 sensor, H2O pump, and full timing set have all been replaced. A fuel pressure or pump problem have been ruled out because acceleration and heavy fuel demand are fine. Problem occurs only when coasting or decelerating between 25-50 mph. Touch the accelerator or even the brake, and surging stops. (?!)

89toycam

Clean your throttle body and EGR valve. Most likely, I think.