High CO emissions, others very low; MAF swap halves CO but doubles HC

MAP sensor needs cleaning or is bad ?

Sounds like you lost O2 Control

Check fuel trim & data with professional
scanner & such

You done as far as working at home, you did all
you can

You have a rich condition (CO)

Seems as though the coolant sensor is not working &
your in open loop

Have your fuel injection pump calibrated. Might as well have it checked for leaking injectors.

Replace your oxygen sensors.
murf427

The HC is high because the CO is high, CO is caused by to much fuel being delivered. You will want to check the Oxygen sensor and make sure it is functioning properly. You will want to check the fuel pressures, including rest pressure. We have seen leaking injectors cause this problem. You will want to make sure the thermostat is working correctly also.

First thing to do is check over the sensors that control the fuel mixture as it sounds like you're runnign too rich. This could be due to a faulty water temp sensor. If this is the problem then the ECU (Engine Control Unit / aka computer) will be leaving the car constantly 'on choke' and not reducing the fuelling as the engine warms - so unplug the sensor and clean the contacts on both sides with some switch / electrical cleaner (not WD40) and inspect the wiring for any signs of damage to the insulation especially where it runs over other components and through the bulkhead

If the engine is running well and the state of tune and ignition timing is good (15 degrees BTDC) then most likely the converter itself is bad. Usually NOx readings will go down as HC and CO readings go up, and as a result it is extremely rare for a car to fail an emissions test with all three things if the Catalytic Converter is working properly.

A bad oxygen sensor can also cause a failure similar to this, but will usually cause HC/CO readings to be high (but NOx readings would be low), or the opposite - high NOx but low HC/CO readings. The O2 sensor is located in the exhaust manifold just before the bulge of the catylst and at the point where the 4 pipes join together.

Unfortunately there is no good way to test the Cat. Highly specialized equipment is necessary to do this, however a temperature test might clue you in to one that is bad.

After driving the vehicle for several miles, immediately check the temperature of the converter at the very front and the very rear of the unit itself. The rear should be at least 100 degrees (F) hotter than the front. If the two are close to the same temperature then it is proof the converter isn't working very well.

I have to note though that temperature testing is far from conclusive. I've seen converters that pass test with flying colors but still ended up needing to be replaced.

Aftermarket converters tend to be less effective than factory converters because they are not built specifically for your vehicle. Instead, a universal unit is welded into some exhaust pipes so that it will fit. Generally this isn't an issue, but if you live in a 'green' state such as California where emissions standards are very strict, it could pose a problem.

Keep us updated.

high NOX indicates your engine is running high combustion temps. Two of the major reasons for lean mixtures are intake leaks and clogged fuel injectors. The reason the engine computer cycles between rich/lean when running is because the cat needs lean mixtures to deal with HC and CO and a rich mixture to deal with NOX. If you are running lean the cat can't lower your NOX. I would first get your fuel injectors flushed and de-carbonize your intake/combustion chambers.

Borrow or change the MAF completely,you have a LEAN combustion condition.The MAF could very well be the problem as it is the most common source lean combustion.
You will need a catalytic converter in good shape.

will rsearch this at work for you and will get back after weekend

Sticking egr will raise everything except nox. Bad o2 bad cat hard to give an accurate diagnosis with out checking it

You cannot retro fit a late engine with vanos to an early model that uses the non vanos set up .There simply is too much else that needs to be changed as well. You best bet is hang in there and find the correct type of engine for your car.