did not pass- "gross polluter"
- replaced spark plugs
- replaced egr valve
- cleaned out egr (under fuel lines)

the smog center guy said to take out head gasket and clean air ways from there OR replace the "cat" and air sensor.

I'm am a novice mechanic at best.

How do I remove the head gasket to get to the airways?

Should I replace the cat and air sensor?

I don't have a lot of money- which would be cheaper?

 

Did you get more information from the test? Was CO high? Or NOx? What you might try, depends on how it failed.

 

And to add to Jim's questions - what do you know about the normal tune up items (cap, rotor, plugs, air filter, pcv and inspect the wires)?