Ok, guys here what it is… I have 09’ Cobalt SS/TC with 25k miles on it. Car is pretty much stock except K&N drop in filter and superchips flashpaq tuned with 20 psi. One day I was driving back home and pulled few gears hard, and everything seemed to be fine… but when I got home, I saw that CEL came on and I realize that when I accelerated – there was no boost... car was driving ok like any other car without turbo. So got home, checked CEL and I got code P0100 which is MAF (mass air flow) sensor. I thought that probably something wrong with my maf sensor or may be coz it got some oil on it from brand new K&N filter. So I cleaned maf sensor with a maf cleaner from autozone, put it back and cleared the code with my OBDII reader… and what happens now it starts and shuts off in about 5 sec., no CEL or anything. I thought may be its bad maf sensor, so I bought a new one, and same problem – starts and shuts off… But when I disconnect the maf sensor, car starts and drives, and shows cel that maf sensor circuit is disconnected. I took my car to a friend of mine, he is car electric and has professional obdii scanner, but he couldn’t detect any problem either because it wont throw any codes, so he suggested to take it to dealer. Did anybody else have the same problem??? I don’t know what to do now and don’t want to take it to dealership… I would appreciate any help, thank you!

 

Did you check that the part number was exactly what you needed? Sounds like you got a bad sensor or something.

 

Did you disconnect the battery for 10 minutes? Probably won't help but worth a shot.

 

I hope that you're able to get this sorted out; if you do end up going to a dealership, please let me know as I would like to be available to assist!
Sarah
GM Customer Service

 

This is a myth. If you are trying to reset the ECU all it takes is for it to have no power for about 10sec's and thats it LOL

Just disconnect the two wiring harnesses on the ECU for minute or so to be sure and thats it. When you connect it back up all the values will be at zero and it will start learning again.

 

yes i checked my old maf part # and bought the same brand new one... and i did disconnect better for 10 min at leat 3 times already but it didnt help either, still will start and shut off.. any other ideas guys?

 

You blew up your IC endtank and have a boost leak, causing a rich condition when you try to start your car. When you start it without the MAF, does it spit out some black smoke? Run a boost leak test. See sig.

 

just tried to disconnect 2 wiring harnesses on the ecu for few min- same thing...ehh dotn know what to do now

 

^This.

Also, just to be sure.... and I know it sounds dumb but, is the MAF sensor facing the right way? lol

 

This is going to sound stupid, but are you sure you have the MAF turned the right way?

Edit: Just saw that^ post pop up after I posted up. Beat me to it.

 

yes maf sensor is facing the correct way... i tried to put it other way it wouldnt fit dou...

 

Check intercooler end tanks for cracks and check to see if the lower charge pipe disconnected.

Mine did this same thing when my lower cp came off the tb.

 

checked all charge piping are connected very tight and clamps are in place and dont see any cracks on ic tank...

 

I found your problem. That bullshit excuse for a tune doesnt account for the dropin and its skewing the readings like crazy causing the car to go into limp mode. Our ECU is very finicky and the Superchips is garbage. Get rid of it man

 

the thing is that i bought my car with superchips tune and dont have tuner itself so there is no way i can put stock tune...

 

Maybe find someone with hpt or take it to a dealer and have them reflash it. If you have one close by you can limp it to the dealer with the maf sensor unplugged.

 

You can't see all of the IC unless you pull the bumper cover. You absolutely, positively, need to run a boost leak test, so gather the materials to get her done........and get her done. I'm going to go out on a limb here and tell you that this is 100% your problem, so get to boost leak testing, find someone who can do it for you, or take off the bumper cover and look for a crack on the coldside endtank, facing the bumper cover, in this area (look at red line):



This is what it looks like with the bumper cover off:



This is a bad temporary repair, waiting on the ZZP IC to come in:

 

finally i got her running with maf sensor connected, by taking off maf sensor from the intake pipe and starting the engine, it started for a sec and shut off... then i put maf sensor back in place and started engine again and car finally started running normally..but no boost at all and cel came on w p0100 and p0101..so according to SSlobalt i have boost leak some how, and ill try to boost leak check it next week and will keep you all informed about results...hopefully it will help me to find out whats wrong with her!

 

p0101 is wet MAF or fucked up, happened to me while tuning, cleaned it and dried and boosted strong again

 

I had that same problem.




Some Gorilla Glue and Synthoglass fixed her up until I could buy my Treadstone IC.

 

ha this thread is full of reall helpful comments and some really stupid comments. i was very ammused reading it. thank u everyone. dear OP i hope u figure out wat the problem is. sounds very strange. cars r a pain in the ass sometimes arent they?

 

Found someone who had a similar issue, if it turns out to not be a boost leak, but you would have to question how it got like this to begin with, like a broken engine mount or something.

https://www.cobaltss.net/forums/2-0l...-rough-270489/

 

Quick and easy way to fry your ECU hot plugging it like that. Guy up here blew his up doing exactly that.

If you're going to reset the ecu remove battery ground first then go ahead and pull the 2 plugs on the ECU. Go grab a snack or drink a beer. Plug ECU back in and hook the battery back up.

DO NOT HOT PLUG YOUR ECU.

 

update: got it started but it has cel p0101, if ill go ahead and clear that up, it will not start again, already tried that... any other ideas?

 

Try boost leak. If it comes back good then I wouldake sure the Maf has a 5v reference from PCM.