High Mileage

Recently bought a 96 F150 w/ 344k on the clock. Got it for next to nothing, so I expected to have a few problems to work out. Right now, it's throwing three separate codes:

• P0141
• P0147
• P0420

The first two indicate that the mixture is too lean in both banks, and I think the P0420 code has something to do w/ a catalytic converter. The truck has trouble starting, but so far has eventually gotten going every time. I do notice a rough idle at times, but it hasn't stalled on me -- yet.

Took it to a local mechanic today because it failed emissions due to the codes (as expected), and he said he found a vacuum leak and repaired it. He retested the truck and it passed, but about halfway home, the CEL came on again and when I checked the codes, I got the same three as before. The truck also doesn't run any smoother than it did before he fixed the vacuum leak.

Anyone have a suggestion as to where I should look next? I'm not interested in spending a lot of money on repairs due to the high mileage and low cost of the truck (paid $700), so I'm hoping to be able to work on it myself instead of paying $65 an hour. I only use it on weekends, and even then it's only a few miles at a time for local errands that I can't do in my everyday driver.

Any and all help would be appreciated!

High Mileage

Whoops, wrong section. Sorry fellas...reposting in the old beater section where I belong.