Context: For the last month I noticed that my car (2003 Mazda 2 [DY], petrol) had some issues accelerating, especially between 2000 and 3000 rpm in lower gears. I had this before and it got fixed by replacing the spark plugs. Today I noticed that the circled hose in the picture was not connected. I assume it got loose since I often have to drive on rough cobblestone. I plugged it back in and immediately noticed that the acceleration issues were gone.

1) What is the purpose of that thing?

2) Do I need to check for eventual damages, or have it replaced/fastened?

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1 Answer 1


Since I can't see much of it, I would assume that it is part of the pcv system and when it comes off it allows too much air into the intake causing your issues.

I would secure the pipe in place with a small zip tie to prevent it coming off again.

  • You're right! I've manage to scour for a tech manual and found a picture which describes it as "PCV hose" i.imgur.com/ekxWIu2.png
    – Lennart
    Commented Jun 2, 2018 at 13:56

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