A quality aftermarket catalytic converter will work fine as long as everything else is in good working order.
it could make it run rough bucause of the o2 sensor but its not going to hurt the motor other than running rough and use more gas
No
The vehicle will fail the emissions test.
It will really mess up the fuel mileage,and driveability
It can, yes. So can a bad fuel mix. Catalytic converters run hot to begin with, and dumping unburnt fuel into a converter can cause problems.It will mess with the O2 sensors causing premature failure.It can clog the converters and actually set the converter's internals on fire.See the related link for more information."An engine that is not performing properly, that is not burning all the fuel, will allow unburned or excess fuel to enter the exhaust system. When this excess or unburned fuel contacts the hot core of the converter it will ignite. This constant infusion of unburned fuel will cause temperatures to continuously rise above the designed operating temperature until the core of the catalytic converter will actually melt. Possible causes for the excess fuel entering the exhaust system are an incorrect fuel mixture, incorrect timing, corroded spark plugs, worn and cracked ignition wires, improper fuel pressure, a faulty oxygen sensor, sticking float, faulty fuel injector or a malfunctioning check valve."
It can not be cleaned. Trying to clean it will mess it up.
Tell your dad to look on the exhaust right after the manifold, there may be 2 of them 1 before the catalytic converter and one after but most likely only the one. It is the only thing attached to the exhaust system with wires connected to it, he may want to get the o2 sensor removal tool which is a deep socket with a slot in the side so you dont mess up the wires.
That is a NO NO. You should never clean the mass air flow sensor it will mess it up.
Misfire on cylinder 3. Get it fixed asap so you don't mess up your catalytic converter.
not by law lol it will mess up you oxegen sensor after a while
A catalytic converter's function is to filter most pollutants out of the exhaust so it probably wouldn't mess up the computer in the car or lower gas mileage. On an OBDII vehicle(post 1996) the computer watches the O2 sensors to monitor converter efficiency If the converter has failed(or is missing) the computer will adjust fuel ratios to try to compensate This can ruin economy,
There should be 2 of them. Upstream and downstream. Upstream means before the catalytic converter(usally screwed into the exhaust maifold) and downstream after the catalytic converter(usally in the exhaust pipe) I have seen in some repair manuals it is located inside the computer,but I have never found one there. Look on your exhaust system first. And they are a REAL PAIN to get out. So dont be discouraged if you mess somthing up, or pay someone that has a heating tourch and knows lots of cuss words. Good Luck with this painfull project....