I have a 2001 Cherokee that I bought and put a lot of money into:
New brakes, exhaust, new cylinder head. lifters, etc.

Now I have two more problems. The computer is giving the P0442 code (small leak in the evap system).

I replaced the gas cap and that did not help. Is there a common problem/solution for this that I don't know about?

Also when the rpms get above 2000 there is a sound like someone is shaking a tin can half full of pebbles.

I have no idea what that could be?

Any help is greatly appreciated.

 

Check the Evap purge valve on the driver side fender well. It is either internally stuck a little open or there is a pin hole in the hose.

 

I looked around where you said and consulted the Haynes manual. I could not pin point the valve you were talking about. I looked at the hoses they all look in pretty good shape.

Any other suggestions?

 

Your tin can full of pebbles is either a bad cat or something rubbing a driveshaft or exhaust leak, most likely. You have a vacum hose somewhere that is leaking, keep looking. This repair may be beyond Haynes manual, scope.

 

You might have too get a smoke test done to find your small evap leak.

 

check all the rubber 90's on your vacuum lines. i had the same code and replaced my purge solenoid, a few rubber 90's on my vacuum lines (specifically the ones right below the throttle body coming out of the intake manifold), and my gas cap. the code hasn't been on since.