Just a warning: If you have a 04 Mazda3, you should consider replacing the tension pulley. The stock pulley is made of plastic, which shattered on me while driving my family home on I-55. The replacement pulley is made of metal.

Due to the fact the independent shop I took my car too didn't fully understand how removing the A/C belt pulley would throw off the timing, I now have cracked cyclinder heads. Total cost so far $4,500+. Cost of replacement tension pulley: $210.

Thanks Mazda...

 

ya that was the same deal at my work.

the guy never changed his timing belt on his passat, and it ended up slipping and bending 12 out of 20 valves....
cost to replace timing belt: $900
cost to fix blow engine: $4500
laughing at the guy for not keeping up with reg. maintenance: Priceless