Gen 2 2008. Changed spark plugs, air filter, cleaned MAF and throttle body. The cat had been stolen, then a replacement was installed. Mileage is 148,000 miles. Before and after the cat was stolen, the mpg was 45-48. One day after Costco gas filling the mpg dropped to 41-42. Tires are 40 psi. Driving is very gas saving. No acceleration. What else can be done to improve mpg? Thanks.
You need to give it time. I never take much notice of the MFD figure until there are 200-300 miles on the tank. I only compare MPG for full tanks with each other.
One day, a Check engine light came up. After 2 days it disappeared. Recently I read the errors with Torque Pro app, and it showed the P0101 error (MAF sensor). I cleaned the MAF again and reset the error. I will update on the consumption later. At the moment I have almost 400 miles run with 2 units of fuel rest. Hopefully, I will make 500 miles.
I had a long trip about 500 miles. MPG has grown from 42.3 to 45.5. The speed was in a range 60-70 mph.
My 2007 had a big reaction to 45-47 mpg after the replacement of the stolen cat. It didn't took long and after a year it went back to 40-43. Mine does more mpg in the hway than street. I don't know why? By the way I'm using a bigger tire instead of the original 185. I still have the original tires brand new and I tried it one time during winter. I cant stand the ride. I don't know why? Been like that since when I bought it 98k miles. Now is 151k. I consider the car running very good to excellent. The tire wear in my car is not even 50%. I can easily do a decent 25k as long as I don't get screwed with a big nail.
After replacing the MAF sensor, MPG gradually reached 55-56. Before, there was an occasional Check engine light pointing towards the MAF sensor.
