1993 Saturn SL1 Problem When Engine at Temp
 

Okay, first off this is my first post and I really love this site because it has helped me turn a $400 piece of junk into a great commuter car, you guys provide a lot of great information, so thanks for that.

Onto to the problem, when I start the car up cold it runs great and idles perfect with the occasional spike in RPMs, but when I get the car up to temperature is when the bogging starts. Shifting gears or pushing the pedal from a complete stop becomes impossible, and when you turn the car off it wont start again because the air/fuel mixture is just waaaaaay too rich.

Earlier this week when I plugged in the code reader I got number 23, which says: Manifold air temperature (MAT) sensor-signal voltage is low or high. OR Throttle position sensor (TPS) error. OR Mixture Control (M/C) solenoid-open or short circuit problems.

So I what I replaced is the temp sensor that threads into the plastic intake air hose towards the front of the car, when I first did this I found that the sensor wasnt even plugged in, but nonetheless replaced it and plugged it back in (without replacing the harness), no success.

Next, I replaced the ECTS, but after doing some research on here I am thinking that over the course of the life of the car a wire was broken off because there is only one wire coming out of it and into a main line of wires (1ST PICTURE). Should there be two wires coming out of this harness? Also after I replaced the coolant temp no longer works, even though it always worked before. So again no success and added another problem in a broken temp gauge.

Thirdly, I replaced the TPS and that was a pretty seamless swap which went perfect. Still no success though.

Lastly, I have included a 2nd picture which was taken from a standing over top of the engine, while facing the front of the car. In the picture is the ECTS that I showed in the first pic, but my question is what is the second sensor pictured that has a similar harness/clip as the ECTS? Is this the MAT sensor that I should replace?

Any advice/insight on what I should do next is greatly appreciated.

Have you tried the o2 sensor in the air box,or try the one in the manifold first come to think of it.

you could also take the electric grease and put it in the pigtails of the tpt in fact the other sensors too.Just a suggestion sense they get hot.

I replaced the o2 sensor on the manifold two months ago, but not in the air box. Where is the o2 sensor in the airbox?

Ok mine is either in the tube coming off the air box or in the box itself,it came unplugged once and ill have to look.But on the other hand i looked that code 32 up just to be sure and it says that its the manifold one.Sensors are weird sometimes.And i also believe theres another one under the car to in the exhaust.Please keep me informed.

Ummm
O2 sensors are in the exhaust system
There are no sensors in the airbox
The 1 wire temp sensor you replaced drives the dash gauge. Not sure what you replaced it with but take it out and put the original 1 wire device back in. Your dash gauge will work again.

You need to replace the two wire temp sensor mounted in the cylinder head. Replace with an ects and connector sourced from a gm dealership.

I have some sensor right there for sure,ill take a pic

its a iat sensor,is what it is.

Yes indeedy it's right by the airbox that intake air temp sensor is. But not inside the airbox when last i checked. I think on the way early ones it mighta been in the airbox....too lazy to look it up right now...

Sw2...can you please do a search for me?

Okay so re-replace the sensors I just installed with a genuine OEM part and my temp gauge will work, great. But as far as the other sensor goes with 2 wires, what sensor is that specifically if I should replace it?