felixrouaud

Hi everyone!
First : sorry for my english... its not perfect I know.

There is my problem. Few weeks ago my car began choking when cruising. At WOT it's ok, but until I get steady(not accelerating) on the rpm, it chokes! This continue until the car is fully warmed up, for like 5-10 min. Last week, it threw P0102 code. The problem continue. I left my car to the mechanic for 1 week. After checking all the ignition, he said the coil on the second cylinder was done. He changed it for a new. The day after, problem occured again. Im running on 91 octane, cleaned my MAF 2 times with MAF cleaner. The problem seems to happen more when it's really hot outside. P0102 still throwing after all this(and I cleared the code before and after all that).

I got a 08 cobalt sport, all stock.

Any idea? MAF broken?

felixrouaud

Bump!?
I've put Injen CAI in this weekend. Surprise, no more choking! P0102 still occurs tho... I erase it and 2 starts later, magic CEL goes on.

Projekt

take it in for warranty

cmatthewb101

iTrader: (4)

After you take the CAI out

USMCFieldMP

iTrader: (1)

Hard to diagnose over the internet... but the MAF is what I'd be looking at.

felixrouaud

My full warranty is finished (had to finish when i have problems...) and MAF isn't included in powertrain warranty I think. I may just order the 45$ brand new MAF from ebay and try it.
BTW, the Injen CAI is pretty awesome got it used for 150$ and I love it! Hate the sound of SRI tho.

felixrouaud

Ok I finally recieved the new MAF after 2 weeks waiting. Unplugged the battery, installed the new MAF, plugged battery back... I let the car run at idle 5 min and then drove for 10 min, cruising on highway. I started the car again, CEL came back!

One of my friend said it may be cause the catalytic converter is clogged or sumthing, which cause to restrict air and maybe MAF gets a bad reading... Ill lift the car and check that tonight.

Any ideas what it may be?

Coblasts

Low input means the signal is not as high as expected.
Connector for maf could be bad,spray with contact cleaner and inspect the pins.
Also the one of the maf wires could be broke or breaking!
Try pulling on them these connection seem to rot where the wire is put in the pin but dont pull so hard as to rip them out.

Heres some info for you
OBD-II Trouble Code: P0102 Mass Air Flow (MAF) Circuit Low Input

felixrouaud

Thanks. Any idea how to check if the voltage on the MAF is correct? Ill check the wires tonight.

Coblasts

These might help
Check the Pink/Black one with ignition on (but car not running) for voltage to ground,think its 5 volt dc.It would be the middle pin.If its not reading anything let me know.
If no voltage present on the pk//bk wire continuity can be checked from the one side of the emmiss fuse(the side without power when fuse is pulled)to the maf connector middle wire
Check the Black and White one for continuity to ground.

Signal wire you cant check the signal but you can check the wire for continuity(not being broken)Its a little more involve and requires check through the pcm connector to the maf connector

Mass Air flow and intake Air Temperature (IAT) Sensor

Pin Wire Color Circuit No. Function

A YE 492 MAF Sensor Signal

B BK/WH 451 Ground

C PK/BK 5291 Ignition 1 Voltage

D BK 2760 Low Reference

E TN 472 IAT Sensor Signal

felixrouaud

Thanx but I will go to the dealership to have this checked. I've got tranny problems (bad synchro on 4th gear I think) and power steering problems too. I don't know if it's worth the bad car while my balt is at the doctor, but at least all will be working properly after!

felixrouaud

Finally they changed the MAF connector and it did it. My 3rd and 4th gear synchro were changed as well under warranty.

Chevycobaltss3

iTrader: (2)

check for a bad maf. wiring issue. also is the maf in correctly. right direction.

Coblasts

A little slow on this one,Ive been know not to read all the threads myself.lol

By the time stamp it looks like he posted while you were typing!

Coblasts

Alot of guys had problems with the wire in the comnector they are kind of tight alot of times and pull out of the pins im the connector but the insulation for the wire is still on the pin so it looks okay,only by pulling on each individual wire can you be sure its not broken.

felixrouaud

Yea it's really tight with CAI on. I hope it wont break again with engine torque. At least I know the problem now. Thx for helping!