Expecting oil and gas companies to charge less than the market can bear is the greatest delusion. The reason they care about the tax is because this is a captive market which still has some flexibility in demand. If the price is too high sales will go down - people will drive less and plan their routine trips more carefully. This is also why the price of gas goes up just before a long weekend - people will drive more, so they can increase price at no risk to sales volume.

So yes, removing the carbon tax just means the oil and gas companies will make more profits.