Ive flushed my coolant system changed the water pump and timing belt, new thermostat and im still overheating cool air is blowing from my vents and temperature continues to climb in my '98 Honda Passport not sure what to do next. someone suggested my catylitic converter could be clogged but not sure how to check that.

What about the radiator? Water pump? Can you check for coolant flow? There could be air in the cooling system? Do you trust your temp gage? Are there overheating issues besides the temp gage showing hot, like coolant overflowing, under the hood, somewhere?

An overheated engine can be caused by anything that decreases the cooling system's ability to absorb, transport and dissipate heat; therefore engines can overheat for a variety of reasons. Let's take a look at some of the most common causes.
Cooling System Leaks
This is the primary cause of engine overheating. Possible leak points include hoses, the radiator, water pump, thermostat housing, heater core, head gasket, freeze plugs, automatic transmission oil cooler, cylinder heads and block. Perform a pressure test. A leak-free system should hold pressure for at least one minute.
Wrong Coolant Concentration
Be sure to use the coolant recommended by your vehicle's manufacturer. The wrong type of coolant and/or mixing the incorrect concentration of coolant and distilled water can also result in engine overheating. The best bet is to perform a complete flush and fill.
Bad Thermostat
A thermostat is a heat-sensitive valve that opens and closes in response to engine temperature. Heated engine coolant passes through to the radiator when the thermostat is in the open position. In the closed position, it prevents the flow of coolant to speed up the warming of a cold engine. When the thermostat gets stuck in the closed position, coolant stays in the engine and quickly becomes overheated, resulting in engine overheating.
Blocked Coolant Passageways
Rust, dirt and sediment can all block or greatly impede the flow of coolant through the cooling system. This can limit the system's ability to control engine temperature, which may result in higher operating temperatures and engine overheating. Once again, a flush and fill is recommended to remove debris.
Faulty Radiator
By passing through a series of tubes and fins, coolant temperature is reduced in the radiator. Leaks and clogging are some of the most common causes of radiator failure. Any disruption in the radiator's function can lead to elevated engine temperature and overheating.
Worn/Burst Hoses
A hose that contains visual cracks or holes, or has burst will result in leaks and disrupt the flow of engine coolant. This can result in overheating.
Bad Radiator Fan
A fan blows air across the radiator fins to assist in reducing the temperature of the coolant. A fan that wobbles, spins freely when the engine is off, or has broken shrouds will not be able to reduce the temperature to proper level, thus possibly resulting in engine overheating.
Loose or Broken Belt
A belt is often the driving link that turns the water pump at the correct speed for proper coolant flow through the cooling system. If a belt is loose or broken, it cannot maintain the proper speed, thus resulting in poor coolant flow and ultimately, engine overheating.
Faulty Water Pump
Known as the 'heart' of the cooling system, the water pump is responsible for pressurizing and propelling engine coolant through the cooling system. Any malfunction of the water pump, including eroded impeller vanes, seepage or wobble in the pump shaft, can prevent adequate coolant flow and result in engine overheating.

get it serviced

First, you must have a properly installed thermostat that is working correctly. Second, Northstar engines are notorious for air in the cooling system after draining and refilling - keep checking the purge tank level after overheating and after the cooling system cools down. Third, make sure your cooling fans are working correctly (relay, fuse, temperature sensor) - check to make sure both are running when it overheats. If all the above is correct, the problem will probably be blockage in the system (try a flush) or your water pump itself is failing.

Air in the system , bad water pump , cooling fans not working ! Maybe you should take to a shop ?

Being the engine is getting old, the radiator and cooling system as a whole, is probably getting clogged up. The Dex cool antifreeze used in GM cooling systems will, over time, tend to gel and clog the passages in the radiator and heater core. I would suggest having the entire system back-flushed. This would require removing the radiator. It would cost a little more than doing it in the driveway yourself, but continued overheating, especially at the temps you mentioned is going to destroy your engine. Having the cooling system professionally flushed is cheaper than a new engine.

your car is severely overheating. take it to a repair shop and have it checked. it sounds like you are low on coolant, if you only get cold air out of vents, it usually means you you have little to no coolant in the system. you could have a lot of air in the system also. try bleeding the coolant system.

How to diagnose an overheating 3.7
It might be the timing belt!

the water pump collapsed, i am a ford master tech, replaced loads with timing belt

Did you check the water pump? If the impeller is broken it will not circulate any coolant.