Hi Guys,
I am having Mitsu Galant 2002 model. I have recently had engine tune up.before i checked the mileage and it is giving 23mpg. Since 2 weeks i had this tuneup, i checked the mileage again after running 150miles. Now it is showing 10mpg. Now i am surprised. Why is that so much difference. is there anything to be done after tuneup? the car mechanic has not mentioned anything like that to me. i am going to take to him again. I just want to post here toknow if there is any thing else needs to be done after tuneup?

Thanks,
mahesh

 

Well where did you run those 150 miles? In the city/town or on the freeway?

 

this morning i have ran 100miles on highway and those 50 are in city

 

A bad o2 sensor can have a big effect on gas milage, check your air filter and make sure its not clogged.

 

i am not sure whether they have changed the o2 sensor but they did air filter change.

thanks,
Mahesh

 

they messed something up. There is no way you should ever get that kinda mileage. Its sounds to me like they forgot to plug something in like the o2, or the MAF

 

You would think but the cel should have came on.

 

If its not a mechanic you trust make sure he did not recycle pieces from his own personal junkgarden, i would then again said like te that something was unplugged but the CEL is a good point.
Is it running rough? any smoke? does it feel heavier when you accel? any differences like that could point us to something out

 

thanks evryone for your comments. i didnot notice any difference. i am going to mechanic today anyhow.

thanks,
mahesh

 

What you can try doing, is removing the negative battery terminal, put your key in the ignition and turn it to drain any excess power, then wait about 20 seconds, and re connect it. That should reset your ECU, and after a couple hundred miles it should start showing a difference. It might or might not work, but its a cheap solution : )