I've had this idle roblem for the last few months, to the point i couldnt drive the balt. It had a rough idle and would turn off at stops frequently. I just got out of the dealer for the 2nd time in 2 days due to the cel kept coming on.

I was advised this car gets heavy carbon build up and the throttle body, combustion chambers, and injectors must be cleaned every 20-25,000 miles. of course they reamed me for $350 but at least the car is running good so far and no cel. Atleast now i know for next time and ill take it to my mechanic for cleaning for less than half the price.

 

How did they clean them? Tear down the motor?

 

there's a tank they hang and connect to your brake booster hose to run cleaner through. They also have a spray they put through the tb and an additive they put in the tank. Cleans it up real nice.

Also if they didn't replace your plugs after they did that you should do so. The additives they use really like to foul them out.

 

I have a 06 ls and had the idle problem where it would jump real bad like 500 1200 500, then it would also die every now and then on off-ramps with clutch pushed in. Took it in like five or six times, they replaced the TB the first time, then put on a new intake manifold the second, then I dont know for sure the next couple of times, and finally the last time they flashed it to the current flash and bingo runs spot on, great now.

 

One of mybuddies just got it cleaned and it works perfect now, he told me it runs better than its ran before, he is on here als as nova-cobalt i think.