Unfortunately there is no maximum on the amount of money you can (or must) spend to repair your PT Cruisers smog check problem/failure. However, there can be help available if you have spent at least $450.00 on a failing car, and it still doesn't pass; using your own money or money from the CAP repair assitance program . It's called the "Economic Hardship Waiver" and it allow you to register your car even if it doesn't pass smog. You just have to show proof that you've spent the $450.00 at a certified smog repair shop. For more info you can call the State Referee's Office at (800) 622-7733.
The CAP Repair Assistance program is designed to help consumers bring their vehicles into compliance with California emission standards. Through the CAP program the State will pay the CAP repair shop you choose up to $500.00 dollars for smog check related repair work performed on your PT Cruiser. You may contact the BAR at (800) 952-5210 for an application.