I have a 2004 Dodge Neon SXT, which I bought used 9 aboutmonths ago with about 41,000 miles on it. After I drove it for a while, I noticed that the fuel economy wasn't that great 18 mpg in the city (way below 25-31 mpg quoted by the manufacturer). I took my vehicle to get serviced to get better mileage: I did a fuel injector service, changed spark plugs and wires, air filter, oil change, etc. Also,a technician at the shop told me that my fuel trim was not up to the manufacturer's specifications, so they reset the fuel trim by erasing the computer chip's memory. After that, instead of getting better mileage, my mileage actually got even worse: it's about 15 mpg right now!I don't know what to do next please help!

 

try testing for codes...u could have a bad/going 02 sensor

 

they did what to the computer.... they can do that......?! what the hell....? if they did all of that, i'd replace the cat. with a high flow cat. and i'd also replace the O2 sensor...if that doesn't fix it i'd say there is def. something wayyyyyyyyyyyyyyyyyyy outa wack.... are you driving with the AC or defroster on alot? b/c if you are that is the reason 100%

 

What do you mean "reset?" Did they just pull the battery cable off and reset the ECU that way, or did they actually re-flash it?