Ever replaced the front O2 sensor?

 

No, but would the O2 sensor cause that issue? 66 miles on almost half a tank.

 

Did you install the stuff yourself or have someone else do it? If someone else installed, maybe something was damaged? Although even if that were the case I'm not sure how it'd cause such poor mileage.

There are definitely a lot of factors that determine what kind of mpg you get but I think it's safe to say exhaust / mid pipe would not change it by that much... if I only got 66 miles to 1/2 a tank I think I'd be very sad : ( Hopefully you get it figured out.

 

Yeah, it's really buggin me. I get the new BDW coils in the morning, so I'll install them and try it out again, I'm REALLY hoping that's the issue.

 

It's just super aggravating because I JUST replaced the engine on it, so I'm hoping that's not the case.

 

Yes...if your front O2 sensor gets gummed up it won't detect enough fuel in the exhaust and it will increase the amount of fuel used at the intake.

 

Checked the codes last night, front 02 sensor wasn't throwing anything weird.

 

Just because there is no code doesn't mean that the O2 sensor isn't having issues getting a proper reading.

 

I believe it's da winter gas.

 

Winter gas actually increases fuel economy. Fuel companies are required to put a lot more crap into their summer gas to make it burn cleaner because peoples windows are down. Once windows start to go up for the colder months the gas mixture changes and more nasty fumes are released but fuel economy goes up.

 

Someone suggested that my ECU is dead. Which would make sense and that I could either do a remap or get a new PCM. But that's $$$$$$$$$

 

Someone is an idiot.

 

if that were true then your car wouldn't start

i have 245/40/18 size tires, kn intake filter, ap mid pipe and a custom magnaflow exhaust. i blame my bumper to bumper traffic for my low mpgs.

have you tried premixing?

 

I have not yet. I put it new coils today, removed the midpipe, and reset the ECU all in an attempt to see if anything will change. I'm feeling that the fuel was running extremely rich, because even a 4k rev would hear backfire...Which it didn't used to when I first put the pipe on. So we'll run it for a little while and see what happens. If the consumption goes back down, I'll just have to wait until I get an AP.

 

backfiring at 4k with an ap midpipe is common, i backfire at 2-3k rpms at times. its the nature of the pipe

 

The difference between conventional summer- and winter-blend gasoline has to do with the Reid Vapor Pressure of the fuel. RVP relates to the volatility of a gasoline. The more volatile a gasoline, the more likely it will evaporate as the temperatures rises; evaporated gasoline contributes to unhealthy ozone and smog levels. Summer gasoline has a low RVP and is less likely to evaporate when compared to the high RVP winter grade. The Environmental Protection Agency says conventional summer-blend gasoline contains 1.7 percent more energy than winter-blend gas, which contributes to the summer blend’s slightly better gas mileage.

This switch over from summer to winter blends usually happens mid September

 

I shoot 2' flames with my midpipe. POW POW!