Hello users. I have a 98 Honda Accord V6 sedan. The mileage I have on the car is like 168,300 miles. When I the car had about 165,000 miles, the car had several problems. One of the main problems is that sometimes on the highway, the car would SLOW DOWN by ITSELF. Sometimes I had to pull over and restart the car. I think my transmission was slipping and it could be. However, last month, I flushed my transmission fluid by using some sucking machine. From the flush, my car could last on the highway and my doubts reduce. I still have some doubts about the car slowing down on me but for like a good month, I drove the highway to college and places and the car didn't stop on me yet. So, WHAT DO YOU THINK CAUSED MY CAR TO SLOW DOWN BY ITSELF? YOU THINK MY CAR JUST NEEDED A TRANSMISSION FLUSH BC MY BROTHER NEVER FLUSHED IT. HE CHANGES THE TRANSMISSION FLUID BUT NEVER FLUSHED THE OLD FLUID OUT OF THE CAR. Also, I TEND TO GET LOW MILES ON THE CAR. ON A HALF TANK OF GAS OR ABOUT 8.5 GALLONS, I GET 110 CITY MILES BUT SINCE I'VE BEEN DRIVING THE HIGHWAY, I GET LIKE 130 TO 140 MILES. IS THAT NORMAL? WHEN I GOT MY CHECK ENGINE LIGHT CHECKED, THEY SAID MY 02 SENSORS WENT OUT. HOW MUCH WOULD IT BE TO REPLACE THE O2 SENSORS? ALSO, YOU THINK MY ACCORD COULD LAST FOR SOME MORE YEARS SINCE IT HAS 168,300 MILES ON IT ALREADY. I HAVE THE ORIGINAL ENGINE AND I REBUILT THE TRANSMISSION ONCE AT 125,000. HOPE TO GET SOME REPLIES AND HOPE MY CAR COULD LAST....

 

Changing the O2 sensor will definately increase your gas mileage, as for the slowing down part I'm a little stuck.

 

slowing down as in wat kind? do u feel that something is holding u back? even if u floor it? it should be your master air flow sensor

 

You have a fuel leak somewhere and you need to find it. the worst milage you can get is 11 (constantly mashing your foot down) city and that would get you at least 170 around town.

Find the fuel leak and I would start from the tank and work your way forward.

 

How do you know I have a fuel leak? Even though I don't drive my car a day or two, I don't lose any gas and there are no leaks below my car? But, where do you suggest the fuel leak can be and do you think I should tell my mechanic to look at it? Thanks for the reply though...

 

having driven a V6 accord, I can tell you from experience that even driving very aggressively, I never seen an accord get below 15 with a V6. just because your car does not leak when it is standing still and off does not mean there isn't fuel leaking when the car is running. Fuel can even be leaking past a bad injector(s) and down into the engine. have you had your oil looked at to see if it is contaminated? Have you even checked your fuel pressure regulator or fuel lines for leaks?. 11MPG is either fuel leak or someone stealing gas from your car and that is not likely since you have a locking fuel door.