Bad Gas milage after headers
02-29-2008, 10:24 AM
#21
My gas mileage has suffered a lil due to the car not being tuned.
Once you install the headers your car exhales better, the front O2 senses this and thinks the car is running lean and adjusts the air fuel ratio to what it thinks would be correct by adding more fuel (running rich). So in return youre wasting a lil bit more fuel, some cars are worse then others.....all you need is a tune.
The rear O2 sensor has nothing to do with air fuel ratio but lets your car know if the cats are working or not.
Once you install the headers your car exhales better, the front O2 senses this and thinks the car is running lean and adjusts the air fuel ratio to what it thinks would be correct by adding more fuel (running rich). So in return youre wasting a lil bit more fuel, some cars are worse then others.....all you need is a tune.
The rear O2 sensor has nothing to do with air fuel ratio but lets your car know if the cats are working or not.
03-03-2008, 01:27 PM
#24
Staging Lane
Join Date: Nov 2007
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yeah my LT1 got 28-29hw/mpg before exhaust and shifter. after that I saw rapid declines, and clearly a less restrictive catback exhaust (if installed correctly) is NOT going to lower gas efficiency, if anything it would slightly increase it. But truth be told, when your car sounds good you will drive it harder. If it sounds like two cans of ***, you're less likely to subconsciously flaunt it, unless of course you're used to driving a fart-canned hatchback around town.... of course then a poor-sounding f-body would sound like joy for the ears.
03-03-2008, 11:13 PM
#28
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Join Date: Sep 2006
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My gas milage has declined as well after headers and td's. I had my car dyno tuned plus they drove it down the road a couple times loggin info to make sure everything was ok at part throttle. Tuner said everything was good. My gas milage sure aint to good since then... i get about 17 around town and not a whole lot better on the highway. Oh yea i also put bosch o2 sensers in when i installed the exhaust.
