I don't know how I overlooked the mention of a cherry red cat, but if that's the case I would have to agree...it is likely to be your problem.

 

I agree with u it was kind of strange to see that LOL but there has to be another problem on top of that because I only had the cat for like 6 months

 

Sorry if I missed items in this thread, but are you throwing any service engine codes? If not, I am suspecting the cat you got is a dud. It does happen, if a manufacturer produces 100s of 1000s of an item, one of them along the way is going to be bad.

The only thing I can think of that would cause pre-mature failure of the Cat is if the car was running way too rich. Otherwise, little things like a mis-fire, should not have an effect. The Cat is getting cherry read because it is plugged up and not allowing the hot exhaust gases to exit efficiently. This could lead to bigger problems with the engine itself, as it will build too much pressure.

Even if there is another cause for the Cat failure, you will still need to have the Cat replaced. I'd go for getting that done first. And again, it could be as simple as you got a dud.

 

I sure do hope so as some as autozone opens up I'm there because I miss the Monte being on the road. But u said something about if there was a code and there was P0300 there was 2 of the same codes on there so I changed the plugs and wires and I was goin to change the coils and ICM but you guys don't think that is it so ill try the cat to see if that does it. Wait a minute I just remember when I did change the plugs one of them was cracked and broken the white plastic coating around the post could that be one of the problems some of that got stuck in there somewhere Idk just a thought

 

If you have a damaged plug (such as a crack in the ceramic), I guarentee that is an issue, it will cause mis-fires (which I believe that code you provided references). Also, when changing plugs, NEVER use BOSCH plugs in GM cars. They don't last as long (unless about 6 months is OK), and just work for crap. BOSCH wires are fine.

Even with a mis-fire, this will NOT cause the cat to get cherry red (going back to a clogged cat).

But if you know or suspect you have a damaged plug on the engine, change it.

Coils and ICM rarely fail. Like I said, ICM can be tested at the parts store. If you have 1 cylinder misfiring (and the car tells you which cylinder), you can rule out the coil by swapping the coil with one of the other two. If it is the coil, the mis-firing cylinder will change.

Also, make sure none of the plug wires are damaged.

 

If it was misfiring and not burning up all the gas that could help plug the cat.

 

I'm at a lost here is what I have done so far:

Catalytic Converter
Fuel Pump
IAC
Plugs
Wires
Cam Sensor
Crank Sensor
Cleaned throttle body
Cleaned MAF sensor
New air filter

But most recently when I tried to start the car I had to step on the gas to get it to come on but it only stays on for like a minute or so and then it stalls and it still idles high when it is on at around 2 RPM I don't know what's left to do

 

A plugged cat can cause a ton of problems. You could have possibly blew a gasket, or you could just need a fuel pressure regulator.

 

I'll try that tomorrow

 

just drive the car for a while and get under it and see if the cat is glowing red, if it is the cat is clogged