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Cobalt
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
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Answers
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,
P0420-00
P0455-00. Only codes that pull on my 2007 chevy cobalt
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,