Will87Will87 Member Posts: 3
edited May 2019 in Chevrolet
Went to put gas in my cobalt and gas started spewing out.... Later it shut off while driving and now want start at all.....any ideas? Had codes for a low performing catalyst and one for a major evap leak??? Cant seem to narrow it down


  • imidazol97imidazol97 Member Posts: 27,103
    Check for hose off on engine or at the carbon canister area.

    What may have happened is the purge valve or the vent valve (built into the canister maybe) isn't working right.

    The evap leak might be causing the inability to get the right fuel trim and causing the oxygen sensor error message.

    Need to scan for code numbers, not assumptions about what they mean. There are different codes indicating which kind of air leak is occuring.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • Will87Will87 Member Posts: 3
    P0455-00.   Only codes that pull on my 2007 chevy cobalt
  • imidazol97imidazol97 Member Posts: 27,103
    edited May 2019
    P0353 is a problem with ignition coil on cylinder 3. P0351-354 are for the 4 coils.

    Short to ground
    Short to voltage
    High resistance
    Open circuit.

    Are you getting spark on any of the 4 coils?

    The Code P0353 is problem with coil firing on plug 3.
    That might _hint_ at a problem with the control of firing the plugs? Did you check the fuse for that?

    The P0420 IIRC is large leak. The vent valve on the carbon canister opens to let air go through. If it doesn't close when car does vacuum test, that's a leak. That closes for the test and the purge valve opens to supply vacuum from engine to the fuel system to test for leaks.

    When you stop the car, that vent valve opens. That allows the tank to vent through the charcoal to catch the hydrocarbon fumes. I would think that includes venting when you're putting in gas.

    However, I had a problem on leSabre that I replaced the vent valve and didn't fix it. Then I took off the purge valve and tested it with voltage to see if it opened and closed properly. It didn't. Replaced it and my leak was gone. Purge valve was cheap for AC Delco from Rockauto.

    The other code you had was for second oxygen sensor finding the catalytic converter wasn't burning off the hydrocarbons. I'd forget that until other problems are fixed.

    Good luck.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • Will87Will87 Member Posts: 3
    Do you have an idea by chance where the fuse is located ??? And ok...i have a guy coming by in a few mins to look it over for me..i will let you know how it goes...whether the problem is fixed or not
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