Ive searched the forum for an answer to this and havent been able to find much. 2006 SC that I got about a month back ran great blah blah blah until about last week in the rain I got into 5th gear and noticed almost zero pick up and lots of hesitation/sputtering to the point it was not drive able.

Talked to the previous owner who had put a CAI on it off of amazon from some place called Monoka Racing. Not sure about the quality of it but its also got bigger injectors, smaller pulley, heat exchanger, catback and has been tuned by a shop. The PO told me that the driver side fender well was entirely replaced from it being busted although the clips are not all intact leaving a small gap where the CAI filter sits.

Ive had 2 shops look at it, tell me nothing is wrong an it drives for a day or so just fine then completely ***** the bed again. Exhaust blow back, almost sounds like someone is rapidly pushing the throttle but its starved for power. Had a mechanic I know hook it up to his computer after a cold start and said it was missing on all 4 cylinders and white smoking, pressurized the coolant system then said it idled fine after warming up but he noted that it could be a bad head gasket letting water leak into the cylinders. I NEED HELP

So could this be from water entering the wheel well onto the filter, or possibly a vacuum leak or am I really looking at a bad head gasket? Dealership wont touch it because of "aftermarket parts" and they dont have HP Tuners. Im stumped at this point and very aggravated as i cant even drive this thing after well over a month.

 

mine used to do this in the rain only, water would drip onto the filter and suck water into the intake and make it lurch and bog pretty bad. I put a hydro shield on it and it hasn't don it since.

 

thats what i was thinking of doing but im not sure what shield to get. It has this off brand intake on it so does it matter what shield?

 

Your mass air flow sensor is getting wet during the rain, throwing off values to the computer.

 

Don't get cold air intakes. Problem solved

 

FYI... The cobalt ss comes with a great intake from the factory.

 

Check the tubing of the cai mine rubbed on the body and made a hole in it the car would almost shut off like driving a stock cobalt. Fixed the hole and never had a problem after.