The ECU was the problem (not anything else!)

[gorkyb]

It's great that your car is running fine now. Just be careful, loose connections are very dangerous, it can leave you stranded at any parking lot when you least expect it. With fixkick's help I tested every pin on mine. What I'd do in your place is to take readings now when it is running fine and write them down, then do the readings with the ECU on it's original place (which is when you seem to have the issue) and find what's different on the readings. Very frustrating to do but with patience, safety pins, alligator connectors ($3 in Harbor Freight) and your voltmeter you can knock this out in a few hours. I had my ECU hanging around also while I was troubleshooting for problems on my car, when I tried to put it back in its original place it was not easy, connectors are forced to make a sharp 180 degree turn facing up (not sure if yours is the same way) plus in cold weather those wires do not form too easily. PO owner on mine tried making a Fast and Furious compact out of my car (probably why I liked it?, guilty!-don't judge me) but it brought a whole bunch of issues on my car. As time went by fixkick and I worked on putting everything back to stock and symptoms starting disappearing one by one. Don't feel bad, I also purchased 3 or 4 parts that I didn't really need for my car to run, but I look at it from the point of view that since Suzuki is going away from the US, having a few extra parts laying around are actually a good investment (if you're planning on keeping the car) I went to the store and got me those briefcase style organizers, threw all my extra parts in it and labeled it "Geo Tracker", I have one for my Civic too. Hey, at least it made me feel a little better, lol.