Alright, my fiance is trying to get a car that was donated to her through emissions. It runs perfectly fine in every way, except when you run it through emissions it always fails because none of the sensors are said to be working. The guys at the emissions center said it was because it needed to be drive cycled, but that wasn't the case at that point, because the car had done that for years, no matter how much it was driven. So, we replaced the computer in it; the ECM, in the center dash (got one from a junkyard for $30). WE HAVE NOT DRIVE CYCLED THE NEW COMPUTER YET. But the readout on emissions is the same, so we have the inclination that it didn't fix anything. Something that adds to this is: her coolant light is always on, even though the coolant isn't low, and it also always says that her back hatch is open, when it is not. So we think there is a deeper problem than simply the computer, but we also doubt every single sensor on the car is bad. So we think it has to be some central processing problem.

Any ideas? Is there an onboard computer besides the ECM that handles such things? Or will drive cycling it fix all of that? Or what? We are at a loss at this point as to what to do.

 

Did you get a code P1000, if not what code(s) did you get?

 

The OBD2 reader reads, "No Codes"

The emissions reading says:
Monitors not ready:
Catalyst
Oxygen Sensor
Heated Oxygen Sensor
EGR System

I am really doubting, as well as hoping, that all of these things are bad.

 

After having a battery disconnected or putting in a different ECU you will get a message saying monitors not ready, because the ECU has lost it's memory. Usually everything will reset itself after about 50-150 miles of driving as long as you don't disconnect the battery or ECU again. Sometimes you can speed up the process of the ECU relearning everything by taking it out on an interstate or road where you can get it up to speed and keep it there for 10-20 miles.