I replaced my stock AST cap with one from Auto Zone rated at a higher pressure rating with a spring. Is this OK, I also used the same type of cap on the filler neck.

 

I'm pretty sure there was a TSB that lowered the cap pressure to 9psi... someone correct me if I'm wrong.

 

The cap with the spring goes on the AST. Mazda lowered the system pressure to 9 psi due to turbo coolant hoses bursting. I doubt the spring cap on the filler neck will hurt, it just will not pressure release. It's supposed to have a cap with no spring.

 

I am using 2 - 16lb caps..

 

so is it bad to have two 16lb caps is what I am asking here??

 

The one on the filter neck isnt suppose to be a pressure style.

The one on the AST should be fine, proper caps lead to proper pressure and curculation

 

I will go back to auto zone then, and buy a new one for the filler neck, thanks