Originally I bought the car off Craigslist, didn't pay attention too to much under the hood, but the car ended up overheating on my way back home, ended up having to replace the water reseviour due it missing the return hose which caused complete loss of coolant and thus it overheated. We have replaced the ac compresser and the tensioner pulley, because they where both completely shot, but now when the car first starts it won't allow me to go over 3000RPM, this doesn't happen all the time though, just every now or than. And doesn't allow me to go over the 3000rpm until I drive around town for alittle while, I had my thoughts on mabey a mass airflow sensor. Any help would be appreciated

 

Error codes the car throws

 

The 0171 and 0174 are indicating a vacuum leak causing a too lean condition. The 0420 is a result of the lean condition. The under 3000 RPM is restricted performance to attempt saving the catalytic convertor.
The most common culprits are:
1. Brake booster check valve.
2. PCV hose
3. IMT seals
4. Intake manifold gaskets.
Since you noted that you had overheated the engine and that it goes away after driving for a given amount of time, I would start with the manifold gaskets.
While the manifold is off I would change the IMT seals. If the PCV hose to the manifold is not the new updated rib style I would go ahead and replace it. You will also need to examine the brake booster line on the back of the manifold and make sure the check valve isn't cracked or deteriorated.
That should address most of the know vacuum leak locations for the engine.