Question on fuel caps

[miri]

I drove off and forgot to put my fuel cap on my 2003 Civic. I replaced it with a generic cap $7 that seems to fit it perfectly. The honda cap was like $30. If the generic cap I replaced it with doesnt fit perfectly, does that lead to worse gas mileage and loss of engine power? I noticed gas mileage and engine performance is worse, but that could be anything.

So the question is, if the generic cap lets in a little air, does this hurt the performance and the mileage?

 

[NutBucket]

Cheapskate. Anyway, if it doesn't throw a CEL it should work fine.

 

[miri]

Originally posted by: NutBucket
Cheapskate. Anyway, if it doesn't throw a CEL it should work fine.

CEL?

 

[MikeyIs4Dcats]

CEL = Check Engine Light

 

[AMDZen]

It should be fine, but it might not pass Emission testing, you will have to wait and see

 

[miri]

Originally posted by: AMDZen
It should be fine, but it might not pass Emission testing, you will have to wait and see

So not having the original gas cap can make a big enough difference to change emissions?

 

[Ime]

Originally posted by: NutBucket
Cheapskate. Anyway, if it doesn't throw a CEL it should work fine.

Kind of what I was thinking. It's a Honda, spend a little extra on keeping it in good shape and it'll run forever.

Cheap parts are for Ford's. 😛

 

[miri]

Originally posted by: Ime

Originally posted by: NutBucket
Cheapskate. Anyway, if it doesn't throw a CEL it should work fine.

Kind of what I was thinking. It's a Honda, spend a little extra on keeping it in good shape and it'll run forever.

Cheap parts are for Ford's. 😛

Ok, ill prob buy a oem gas cap, didnt think that the fuel cap made that much of a difference. The generic one seems to fit perfectly but I cant tell if there is any air leakage.

 

[CRXican]

Originally posted by: miri

Originally posted by: AMDZen
It should be fine, but it might not pass Emission testing, you will have to wait and see

So not having the original gas cap can make a big enough difference to change emissions?

they do a gas cap test to make sure it isn't to wussy

 

[miri]

Bump, does a OEM fuel cap make a difference?

 

Originally posted by: miri
Bump, does a OEM fuel cap make a difference?

No,
I can't believe you are actually asking this question.

 

[Heisenberg]

As long as the CEL doesn't come on, I wouldn't worry about it.

 

[Vic]

Originally posted by: Heisenberg
As long as the CEL light doesn't come on, I wouldn't worry about it.

Exactly. Modern cars have pressurized fuel systems. The smallest leak in the system will trigger a CEL. If no CEL, then no leak, no worries.
A leaky gas cap will cause lower gas mileage because gas vapors could evaporate out of the tank. So you're not actually getting reduced mileage per se, but you're losing gas out of the tank (as if you had a hole in the tank dripping gas). Once again, no CEL, no leak, no worries.