2007 Suzuki Forenza (Page 1/1) FieroJam AUG 31, 08:20 AM A coworker of mine is having an issue with her 2007 Forenza the oil fill cap keeps popping off whiles she is driving. I believe that she had the PCV valve replaced recently but this keeps happening. Any ideas what could be the cause? Stubby79 AUG 31, 11:24 PM PVC somehow installed backwards? Doubtful, but hey... carnut122 SEP 02, 08:56 AM Sounds like you have a plugged PVC system.