I picked up a 96 vanden plas recently to replace the one that got rear ended and totaled last year. It threw a code a couple of weeks ago and could not read it at the auto parts store.

I have since bought a low end code reader and the first time I tried to use it it took me a while to finally get something, I think it said dtc not stored, so I cleared it. Now a couple of weeks later I get another cel but this time when I plug in the reader it gets power but reads "linking to vehicle" and "waiting for vehicle to respond" but then goes back to home screen. It does not read codes.
I tried the reader on a 2007 Impala and it works fine. I have read on the forum about ecm corrosion problems is there anything else I should be checking? Not being able to read codes could be a big problem.