Toyota Repair: Failed MAF sensor, fuel pressure regulator, cleaning maf sensor

Question
my 1991 car runs to be fine without MAF sensor. It failed emission test recently with very worst numbers (almost 120 times the actuall allowed values) for CO. I got it checked with mechanic, he says MAF might be a problem as he tried without MAF sensor car seems to be doing better (but still fails emission test, numbers are not that bad). Is there any possibilty of cleaning MAF sensor ? or is it ok to run it without MAF sensor ? It still emits smoke where else could be the problem ?
Any help is appreciated

Answer
There is no way to clean the sensor it is sealed, the engine is obviously running way too rich, by disconnecting it you are removing the input signal to the ecu and somehow it sees this as an indication to lean the mixture somewhat, you can try changing the sensor but I think the problem is elsewhere, basically, too much fuel and not enough air,this could be caused by a restriction in the intake air system, a leaking fuel injector, a bad fuel pressure regulator or even a failing ecu.