how can I go back to using regular gas
Your '06 Colbalt LTZ has a 2.2L 4 cylinder that calls for Regular Unleaded...if you were using Premium, you were wasting $$. It's not a problem if this is the case, just start using Reg. Unleaded..you can always use a fuel octane booster, if you want to...Not sure if it's even worth the $$ or the trouble though.
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