Ive got loud knocks coming from passenger side cat...when engine heats up...Ive checked for loose strapes and if it was coming from heat sheild..no joy!!.Does it just mean i have a bad pass side cat and if so ..I stay in CA. so am i bound to purchase oem replacement or are there any aftermarket cats that may be alittle cheaper to purchase that will still pass smog?

 

2003 ford f150 supercrew fx4..20in Helo875..33x12.5x20 Federals..aftermarket headlights..5.4 engine

 

Was the truck originally produced for Cali or was it purchased in another state and brought in.....makes a difference in prices?????

Go to hottexhaust.com and plug your info in they have direct fit replacements, also search the Internet for coupon codes...makes a big difference

Btw your truck has 4 cats two each bank

 

It looks like you are in the San Dimas or Glendora area from the pic. There is a shop in Norco that has always been fair to me, De Anza Muffler. You can give him a call.

 

A quick search of the CARB website shows that aftermarket Cats are available in California for the 2003...I have a 2005, and am not so lucky...$2400 for a new Ford cat...