Hello, 'my name is Jarek and I've recently purchased an 08 cobalt. Had work done to it and runs great. Took it to e check and 3 times now they say the computer will not run tests on my car because it's still running diagnostics.. it's been a month now of driving it around. I have even borrowed a friends scanner and read the I/M monitors there's 4 problems. The HTD catalyst, Sec air system, A/C refrig monitor, and EGR System are all n/a. I've tried 3 different drive cycles over and over but they don't help reset. I just don't know what to do anymore. Please help.
My car has 148100 miles.
My car has a manual transmission.
You are looking at the wrong monitors. The one’s that are NA, your car doesn’t have and you should pay no attention to them. What you should look for is complete, and incomplete. You are allowed to have one test incomplete and the car will still pass. The tests take certain driving criteria to run, each one it’s own criteria. Here’s what I would do. Disconnect your battery overnight. Cars computers have weird glitches sometimes. In the morning, start the car and let it run for 10 minutes before you drive it. When you drive it, concentrate on using steady throttle. The drive should include a long acceleration, a long deceleration, and at least 5 minutes of steady 45 mph +. When you are done with your drive, let the car idle for 10 minutes. Re-check your monitors and repeat if necessary, letting the engine cool down before starting again. If the Check Engine Light comes on, it will need to be repaired. Also, the fuel tank should be 1/4 to 3/4 full. If you need help, consider YourMechanic.
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