So on my 2005 Cobalt SS/SC I have an issue when in 1st and 2nd gear. When I go to accelerate in between 2k and 4k it feels like I am downshifting at 5k rpm. It feels like I am slamming the clutch but it happens several times in about 2 seconds. To the point where it jerks me all the way forward in the seat and slams me back into my seat. This happens under normal acceleration (no boost on supercharger). If I press on the gas pedal during this when it stops it has major hesitation then catches back up. Never happened in any other gear and only happens two or three days then quits for a week. Also never really have it above 4k.

I thought it may have been the fuel filter because it needed to be changed. But that did not stop the problem. It will throw a code after a while but didn't make it to the shop to have them run the code before it went off.

Any suggestions would be appreciated.

 

It can be alot of things.... Get ahold of your tuner and log.. prob a dirty maf or somthing similiar..

 

Well what you don't know is you are my tuner....very soon

 

I can ask our Technical Assistance Center to see if they'd be willing to provide any input on this; however, we generally prefer to have vehicle concerns looked into in person at a service department. To check with TAC, I do need to have the last 8 digits of the VIN (private message, if you like?).

Best,
Sarah
GM Customer Service

 

^ don't... And I can see cvery soon to what it is lol. Possibly tune.

 

i have multiple codes coming up. P0446, P0300, P0171,P0420.p0446 is evap vent solenoid performance,p0300 is random engine misfires, p0171 is bank 1 fuel trim lean, and p0446 is cat converter low efficiency.
Any suggestions on where to start?

 

MAF Get wet ?

 

Grim, are you catless. Are you tuned.

 

gmpp tour cat back. it is tuned as well.