I have a 2008 Equinox, it was my mothers car which she gave me years ago when she couldn't drive anymore. The mileage is at 50K, the car runs perfect and never had any problems. I recently failed the state inspection 3 times, first it was the O2 and EGR monitors not ready. After doing some searches I read that the battery may be too old so I went to disconnect the battery but the negative connector was hard to get off and then the battery terminal started to pull out of the battery, the battery was 6 years old so I picked up a new one, after getting the connector off I saw groves in the battery terminal and why it was hard to get off. Then the short negative battery cable connector broke off, I crimped on a new connector, drove 300 miles and still the O2 and EGR not ready but now the Evap is not ready. I took the vehicle to a mechanic, they checked all the sensors, everything is fine, no error codes, no check engine light. They suggested I do the software update on the PCM which I did, drove the vehicle another 300 miles and still the same 3 monitors not ready. I called the mechanic and they told me you have to drive it more and that those vehicles are fickle. After 300 miles, I'm doubting anymore driving will make a difference and I wonder why it failed the first time when some 9 months ago I had a new radio installed and since then it has been driven a few thousand miles. It does not sit, it gets driven nearly every day. I wonder if I should replace the negative battery cable and that perhaps the short battery cable that broke off had a weak connection and why it failed the first time. I need this vehicle, it is reliable and has nothing wrong with it, if I can't get these monitors to turn on I may have to junk it. I can't afford to buy a used car and deal with unknown problems. If anyone can help it would be very appreciated, my 30 day inspection extension is up and don't know what to do. Oh, and I put in a new engine air filter, into it $500 already, all for a an inspection, if they did it the old way would have passed!!! Thanks, Bob