Not sure if anyone has had this issue or not. Due to the incresing thefts of gasoline out of peoples tanks I decided to get a lock n key gas cap... turns out these caps don't create good enough seals and it causes the check engine light to come on. Went to the service shop and they confirmed this. They've had this issue happen quite frequent with the lock n keys...

Just though I'd share this with you...

ps the one I bought was from autozone...

 

Here's a thread about this subject:

https://www.chevyhhr.net/forums/general-hhr-4/do-i-need-locking-gas-cap-14910/

 

I have had mine over a month now with no issues... I just make sure to turn it till it clicks several times not just one click

 

Is it one of the CST brand caps? I have one and the problem with them is that the nubs on the cap neck don't allow enough travel along the metal filler neck rails before the cap gasket friction binds against the filler neck lip-- mine feels like it only turns maybe 1/2" before it binds and the clicker kicks in and you can't turn the nubs further. Bad design. I truly wish the Stant brand locking caps would clear the fuel door and let it close properly-- they would have to be better than these ones.

 

I don't remember the brand name on it but I did get it from AutoZone

 

Just to check, I called a Chevy dealer's parts dept this morning, regarding if GM has a locking cap. They don't. He said Chevy does not have one for the HHR.

My main reason for having one is peace of mind that no one can easily put a contaminant into my fuel tank.