bad gas mileage

hey i just had my turbo, manifold, alternator, and alt belt replaced. Well, my check engine light came on like a week or 2 ago and now, it seems to miss on the highway, does not take off nearly as fast, and i get about 90 miles to the tank, which turns out to be an awesome 6 miles to the gallon. i dont think it is a gas leak because i do not smell fuel. Please help if you can.
Thanks
Lance



92 talon tsi awd
all stock
auto

Do a basic tune up, like change spark plug, and wire, air filter, gas filter, change oil, balance yur tire ( and aligment ) and put enought air on it, put in a bottle of fulse inject cleaner, clean out the TB. and your car is auto turbo, it will eat alot gas then a manual turbo, dont let the rpm pass more then 2.5k, push the gas pedal slow. Good luck with the car.

it could be the o2 sensor

it could be the o2 sensor

yea change that too.

where is tho o2 sensor at in the car

and could that cause the mileage to be that bad?

it's most likely a bad 02 sensor, it's located in the 02 housing right after your turbo (connects to downpipe) When this fails, the car doesn't know the a/f ratio at all so it just goes into "safe mode" and sends as much fuel as possible. 9-10 mpg is about right for a failed 02 sensor. It could also be a bad exhaust leak somewhere around the 02 housing, causing the 02 sensor to get a bad read on air.

"...6 miles to the gallon..."

Owned

Go to Autozone and have the codes pulled. Get a new O2 sensor while you're there too.