Very Poor Gas Mileage

My mother has a 2001 Olds Alero with about 70K on it. Recently the check engine light came on & she had someone run the codes on it. The code came up for “emissions leak”. She has noticed a severe drop in her gas mileage in the last few weeks. Literally a half a tank of gas will be gone if she drives 40 to 50 miles. She’s been told that the “emissions leak” code could be any number of things, including the catalytic converter.



The car runs great. No noises, no stalling, nothing. Just horrible mileage and “emissions leak”.



Any ideas what she might be looking at as the cause?

Ask her to stop at the local Autozone and have them download the codes for free. Post the actual codes here.

No “emission leak” is going to cause that serious a drop in mileage. I suspect there’s been a misunderstanding somewhere in the communication chain of events. Or perhaps a misperception about the actual mileage. Or both.

Thanks. I just sent her an e-mail and told her to get to Autozone and to write down the code numbers this time. I will be back with the info as soon as she gets it to me. Thanks again.

So at best, the car is getting 10 mpg?

If there is not an Autozone near her, most chain auto parts stores like that should have code readers for loan at no cost. Advance Auto does near me. I think I recall someone saying O’Reilly does, too. Mom can call ahead to make sure they provide the service.