Okay, ill start from the beginning. Bought the car and it ran fine until we got about halfway home then it started running rough. Then it ran fine for a couple weeks and then all of a sudden it died. The car would crank but wouldn't start. After wasting thousands taking it to different shops and then the dealership, the general consensus was that the ECU was fried and the dealer wanted about $3000 to fix it so I decided to start looking at it myself.

The first thing I did was pull the ECU out and I found green corrosion on some of the pins, a few of the connectors on the harness, and there was also some brown corrosion residue in the bottom of the box that holds the ECU and TCU. I looked around online and found that these cars sometimes have a problem with water getting in the box. I cleaned the pins and connectors up with some electronic cleaner and bought a new ECU relay like I was told but still no luck.

I started unplugging every sensor I could see to check for damage and after unplugging the Air Intake Temperature sensor on the manifold I found a bunch of weird green liquid inside the sensor. I cleaned all that up and boom, the car actually started but was still running awful. Rough idle, Misfire, dropping RPMs to the point where it seemed like it was gonna stall, and had very little/delayed throttle response. I continued to poke around and found the same green liquid inside the Crankshaft Position Sensor, cleaned it up, and the car was still running same.

New Parts: Plugs, Coil Packs, MAF, Throttle Control, ECU Relay, Battery (ill look at recipts when I get home to see if im forgetting anything)
I have tested fuses and they all checked out. The car has the EPC and Check Engine light on. I know codes would help but im trying to see what I can do before I spend even more money towing it somewhere.

Thanks for taking the time to read this, im on the verge of just scraping the damn thing and would like to know what your guys next course of action would be.

 

Best to begin with the car's year and engine type.

I would have definitely tried to pull codes before spending thousands at a variety of shops. Did none of them tell you what happened when attempting to pull codes? How did they all decide the ECU was 'fried'? If they could communicate with the ECU, then it probably was working (internally), however the contaminated connections are probably involved as you suspected. What color is the coolant? There have been cases of coolant getting into wiring and traveling up to the ECU by capillary action, so look for evidence that coolant has been leaking.

So far all of this assumes the problem is related to the ECU, but maybe it isn't. Do you know for sure that the fuel pump is running and putting out adequate pressure? How is the compression on all cylinders? Coolant temp sensor and MAF sensors OK? Perhaps try disconnecting both of those so the ECU substitutes guess values, and see if the running improves.