My engine light comes on and reads p1000 and p0420. Iv'e removed and replaced brake booster, IMT o-rings, and the hose on top. I hear no obvious vacuum leak. When I get up to about 60mph most of the time the Cruise not Available comes on. It goes away once my speed is lowered for a short period of time. I scanned for codes again and I sometimes got the codes for random misfire and misfire on cylinder 1,3,5. Also 4 years ago I had upper and lower intake seals replaced. As well as new spark plugs. Any thoughts?