Contour Enthusiasts Group Archives Forums General Troubleshooting PO430 and PO174 revisited

1996 Ford Contour SE 2.5L V6 5spd, 123,000 miles.
About 2 weeks ago it chucked its waterpump (1st one at 20k, this one at 120k...). Dealer (ouch) changed the pump, now (a bout a week later) throwing CEL codes PO430 Catalyst effieciency below threshold and PO174 system too lean.
Shortly before this happened, I had a CEL and Autozone said it was an 02 sensor. I looked underneath and the sensor was laying on the manifold underneath the motor. I screwed it back in and the light went off for a week or so, then came back on (they never let me see the original code though).
The cats were replaced under the recall in like '97 or so.
What I want to hear is that cleaning the T/B and swaping that O2 sensor will make the light go off and my car will be happy again.

I searched back and found some debate on if those codes are even related. I also didn't see any feedback if the issue got resolved or not.

Oh, and the IMRC was rebuilt about a year ago, with presumably new gaskets and seals.
The old thread I found on topic was here:
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=trouble&Number=485586&Forum=trouble&Words=430%20174&Match=And&Searchpage=0&Limit=50&Old=allposts&Main=485586&Search=true#Post485586

If that helps.
Thanks

Anyone have any thoughts??

Give your idea a try. Can't hurt, and is good for the car.