1997 Metro, Service engine light

My sister-inlaw has a 97 geo metro. the service engine light came on and she called me. i took my snap-on modis over there and i get no communication with the KOER. i turn the key off and turn it to the run position and i can get data. the comp says that there are no codes, but as soon as i start the car i loose communication between my scanner and the car. i replaced the ecm and i now get 5 seconds after i start the car and as soon as the service engine light comes on i loose commo. i talked to my friend that works for cadillac and he got on chevy's website and told me that i need to look for a problem around the EGR and disconnect sensors one at a time to see if i can get commo back. i tried that and still got nothing. i really could use some help on this one.

check the sensors, to make sure they are not dirty... if that doesn't work it maybe an O2 sensor that is bad or the 02 sensor itself.. I had the same problems with my 96 prism lsi.. unfortunately, unless i replace the 02 sensor ($300) the light will not go off.. my 02 sensor is fine and the connection is just no good.. you maybe having same problem... hope it helps..

turns out the problem was the ecm fuse, kinda messed up. my father in law who already thinks i'm worthless had someone else look at it and they found it. looks like nothing good for christmas again this year

ECM fuse? :screwy: I've taken dozens of metros apart, and never ever seen an ECM fuse. If the fuse to the ecm was blown, it would get no power, hence, it would not start. Someone's blowin smoke up your skirt :icon16: . Could have been a fusible link in the wiring harness, but I don't think Suzuki has ever used fusible links. They're just a bad idea. And one thing, there IS a fuse for the ECM, but it's just to complete a circuit to get the check engine light to flash. So, whatever was causing the problem is probably still there...

97 should be a OBD II, did they still have the fuse then? thought you had to have a code reader to get codes out