# Need help from "car people" (Honda Civic) **URL:** \ **Category:** Factual Questions\ **Created:** [July 18, 2018, 11:31pm UTC](https://boards.straightdope.com/t/need-help-from-car-people-honda-civic/818175 "2018-07-18T23:31:20Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [July 22, 2018, 12:51pm UTC](https://boards.straightdope.com/t/need-help-from-car-people-honda-civic/818175/21 "2018-07-22T12:51:35Z")
> [@am77494](#): > > For my car, 2008 Civic, I couldn’t find the vacuum leak either using the WD40 or Propane either. This is because the booster is well hidden and it’s hard to spray or take propane near it or the associated hoses… Jesus!..you got that right! I had a helluvatime reaching back there. I rigged up an extension “wand” and was able to effectively reach all that I could **SEE**. My only concern is what I didn’t see. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [July 31, 2018, 1:41pm UTC](https://boards.straightdope.com/t/need-help-from-car-people-honda-civic/818175/22 "2018-07-31T13:41:10Z")
Installed the above mentioned sensors and PCV yesterday. The car immediately started running “normally” but it’s too early to tell how this may affect MPG… More later. ---
**Author:** ![Dead\_Cat](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@Dead\_Cat](https://boards.straightdope.com/u/Dead_Cat)\ **Post date:** [July 31, 2018, 4:28pm UTC](https://boards.straightdope.com/t/need-help-from-car-people-honda-civic/818175/23 "2018-07-31T16:28:57Z")
I’m no mechanic, but it seems to me that perhaps the most obvious cause of a sudden drop in fuel economy hasn’t been mentioned yet - hole in the fuel tank. Though I can only imagine this not being immediately noticeable (by way of a puddle of fuel on the floor where you park) if the leak is high up in the tank so that fuel only leaks when moving around. And granted, it doesn’t explain the transmission issues, but that could be coincidental. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [July 31, 2018, 5:33pm UTC](https://boards.straightdope.com/t/need-help-from-car-people-honda-civic/818175/24 "2018-07-31T17:33:51Z")
It passes the smell test. I’d think _after all this time_, if the fuel system had a leak, the odor would have hit me at least once. It hasn’t. I had the thing on a lift awhile back and visually checked too. No wet spots or stains from seepage, nothing. Not very scientific, I know… but I don’t think there are any leaks. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [August 1, 2018, 5:54pm UTC](https://boards.straightdope.com/t/need-help-from-car-people-honda-civic/818175/25 "2018-08-01T17:54:07Z")
> [@Dead\_Cat](#): > > I’m no mechanic, but it seems to me that perhaps the most obvious cause of a sudden drop in fuel economy hasn’t been mentioned yet - hole in the fuel tank. Though I can only imagine this not being immediately noticeable (by way of a puddle of fuel on the floor where you park) if the leak is high up in the tank so that fuel only leaks when moving around. And granted, it doesn’t explain the transmission issues, but that could be coincidental. Doesn’t explain the rough idling or power loss either. ---
**Author:** ![MikeF](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@MikeF](https://boards.straightdope.com/u/MikeF)\ **Post date:** [August 1, 2018, 5:59pm UTC](https://boards.straightdope.com/t/need-help-from-car-people-honda-civic/818175/26 "2018-08-01T17:59:21Z")
Dead Cat beat me to it. Perhaps someone is stealing your gas, 5 gallons a time? Fuel gauge won’t move that much. Not that gas is so expensive that anyone is stealing it these days. ---
**Author:** ![sweepkick](https://avatars.discourse-cdn.com/v4/letter/s/87869e/32.png) [@sweepkick](https://boards.straightdope.com/u/sweepkick)\ **Post date:** [August 2, 2018, 4:06am UTC](https://boards.straightdope.com/t/need-help-from-car-people-honda-civic/818175/27 "2018-08-02T04:06:09Z")
Clean the MAF sensor. Use special MAF cleaner, not carb cleaner or alcohol. [![](https://img.youtube.com/vi/qahCVXcAsNw/maxresdefault.jpg "2006 - 2011 Honda Civic Si MAF How to Clean Mass Air Flow Sensor") ](https://www.youtube.com/watch?v=qahCVXcAsNw) ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [August 10, 2018, 5:44am UTC](https://boards.straightdope.com/t/need-help-from-car-people-honda-civic/818175/28 "2018-08-10T05:44:05Z")
MPG update: Since I replaced the sensors, my MPG has increased to 33 based upon about 4 gallons consumption, with a lot of idle time involved while warming up/“working on” the situation… Not quite the 40+ I was hoping for, but it’s an improvement. [Previous page](https://boards.straightdope.com/t/need-help-from-car-people-honda-civic/818175.md?page=1)