Boost Leak=Horrible Gas Mileage?

[RedTalonTsi'91]

Hey Guys,

I've got a 91 talon tsi. It doesn't really boost until about 4000 rpm and then doesn't pull hard after 5500 rpm. Pretty sure it is a boost leak. I don't have the equipment to do a boost leak test so I need to get that together. Just wondering if a boost leak would effect my gas mileage. I'm getting about 11-12 mpg. I've only owned the car for a couple of weeks. It is all stock.

 

[delta448]

Yes. A boost leak will kill gas mileage.

 

[1992awdlaser]

Yes, it can have an effect on your mileage. I doubt it would have that much of an effect by itself though. Suspect a bad o2 sensor or coolant temp sensor.

 

[RedTalonTsi'91]

Yes, it can have an effect on your mileage. I doubt it would have that much of an effect by itself though. Suspect a bad o2 sensor or coolant temp sensor.

Thanks, I will check those as well. I'm thinking about changing the spark plugs, fuel filter and other general maintenance parts to see if that helps as well.