i have been trying to fix idle problem on my 07 cobalt ss/sc and it has injin cai and not throwing a code for the maf being bad but i only code it did throw was bank one sensor one but it was bad 02 sensor replaced still idle shitty bouncing rpm and idles surging when at stop light it will go from bout 800rpm to 300rpm then bounce back up enuff to wear lights dim, dose it the worst when heater/defrost is on??? wanting to no how to test maf with a voltmeter tester and the decimals at idle and rev????? THANK YOU

 

Did you clean the throttle body,
Doing this seems to cure idle problem for alot of guys,but be careful you dont damage anything.

Less is more with the spray,Procedure is to spray the cloth and clean and not spray directly on the throttle body
otherwise you may soak a sensor and they are quite sensitive.

 

Mines is doing something similar except I clean the tb and surging stopped at idle but not it throwing the bank rich code and the P0300 random misfire code.

 

The maf canot be tested with a meter,The info going back to the pcm can only be seen with a tech 2
or purchased software,

 

My Saturn ion redline was idling like **** up and down. The fix.. Replace coolant temp sensor and thermostat and it with fix idle. Parts are around 50 dollars at auto zone or advance.

 

Clean the TB I clean mine once a week its surprising what kind of grime gets in there and enough can mess with the TB.

 

you had the pcm tuned mine throws a random misfire but mines still not tuned

 

Wait what? How would that fix the idle surge?

Same issue here. Coming up to a light or taking it out of gear while moving faster than 10 mph causes mine to jump. Calm down once I'm stopped. Even died on me a few times.