i have been having horrible problems with my 2008 ls after i went catless. under acceleration it randomly sputter/drop rpms for a second. it ocasionally dies as well while driving. if i give it full throttle (again randomly) once i put it in second it will drop rpms and backfire obnoxiously. the second oxygen sensor has been replaced because the wiring was cut. i do have the vibrant defouler. i went to get my codes read and my car is showing a code for both oxygen sensors and the MAF. visually there is nothing wrong with the MAF i have cleaned it but still throw a code for it. where i am stumped is that it is completely random when these problems occur. i figure if it was the MAF it would just be a constant idle/throttle problem. has anyone experienced this? i would much appreciate any comments and ideas thank you.

 

Find someone near by and swap maf's and see if it makes a difference or clears your codes. If you have a maf code then your maf is out or going out. I'm pretty sure (someone who knows correct me please) if your maf is not working properly then the computer adjusts fuel injection by the oxygen sensor, so if both are messed up it would flip out and sputter or die.

 

unfortunately i dont know anyone who has a cobalt. im going to try the oxygen sensor first since its cheaper. thanks for your input it makes sense

 

ok so i found someone i know who has a malibu. so i swung over there today to try his MAF. the car started and seemed a bit more rich than before. no cel. took it for a drive and no cel came on. yet i still had the problem of it sputtering. changed it back to my MAF started it up and within a few seconds it had a cel. now i am just as lost as i was before. so possibly both are bad?

 

Yeah i'd replace both, or at least start with the oxygen sensor and then grab your friends MAF and try again.

If your car still under warranty?

 

It is under warranty but my stock exhaust is unusable so im afraid that they wouldn't warranty anything. Now I heard that it is vital to replace the oxygen sensor with stock replacement. What do you feel about using a denso brand sensor?

 

update: after replacing the MAF sensor and oxygen sensor. i learned that there is an oxygen sensor fuse. checked my fuse box and the abbreviations are a little cofusing but i found one blown fuse labled exh. changed it out took it for a drive. code has not come back on after a few miles and a few start ups. but on first start up it idled like ****, it loped to near death. gonna take it for a longer drive to see if the problem persists.

 

after about 15 miles of driving a few start ups i still dont have a code but the problem still persists. it still sputters and dies randomly. anyone have any ideas?

 

Dude, I know how you feel....I'm going through a similar situation myself, I feel like just putting a brick on the gas pedal and letting it drive over a cliff thats how Frustrated I am Good Luck

 

lmfao ive said the same exact thing! ill keep the thread updated until i find the solution. researching the problem with no avail. it seems that nobody with a cobalt has posted the problem with a solution yet.