I bought a truck off my father inlaw just something to play around in and as a second car for when my wife works the morning. it won't pass aircare I was told it needs a new catalytic converter. thats about 517.00 for a direct fit and 260.00 for a universal. a little out of my price range since there is alot of other things to do to the truck. its a fixer uper.

what else could cause the truck to fail an emissions test? It starts the first time and runs good. has about 300,000 km on it
its a 302 V8 not sure if there is anything else. Its been sitting for little over a year.

 

km??? Are you in Kanadia?

Leaving it parked (neglected) is one of the WORST things you can do to any vehicle. A year of neglect is probably twice as bad as a year of abuse. The first thing to do is THOROUGH maintenance. Buy a Haynes manual (PN 36058 w/light blue cover) & read chapter 1. Then go buy what you need & follow the instructions on the emissions sticker under the hood. It'll look like this, but use YOURS.



After that, DRIVE IT. It needs to be run for a while to burn any crud off the cats so they can work right. Make sure there are no vacuum leaks & that all the emissions equipment is working correctly. You can find plenty diagrams & photos like the one above thru my signature link.

 

Any vehicle can pass a smog test with a good cat, but it has to be working, and should be as hot as you can get it just prior to the test. If your cat is bad, all the work in the world won't get it to pass until you replace it.

 

Also run a can of seafoam through it. Itll clean out all of the buildup. After sitting that long the plugs and wires are gonna have rust on the connections too. And pull the cap off, ill bet the contacts and rotor are corroded to hell too. (I used to have an 85 Grand Marquis that sat in a field for about 1.5 years)