Okay, so here's the story:
I got this LS 3.0L Montero from my family for graduation back in NJ. Treated me as well as a '94 car in a land of salted roads would and it managed to get me all the way across the country to CA, where I now live.

Following my plans to sell it once I got here, I looked into getting it registered. Since CA has the most ridiculous emissions standards in the world, it of course did not pass the smog test.

Since my cat isn't too bad and none of the vacuum lines seem cracked, I narrowed it down to the EGR. For two months I looked for the thing, bought the manual to the car and no luck. Now my power steering lines went and upon taking it to a shop to get fixed for that, I asked and they can't find the EGR, either.

It's in the manual, and the car is 50 state legal, but is it possible that it simply does not have one? And if so, what are some ways other than replacing the cat to cut NO emissions?

Now I'm wondering if I can't try to sell it to someone in nevada or oregon because other than the smog and the steering lines (which are being fixed) it's still worth a lot more than scrap but I just want to know my options.

 

The EGR Valve is located:
Under hood, center, rear engine area, mounted on rear passenger side of engine

 

I know, it's supposed to be there and it's not. That was the point.
I, and now a mechanic have not been able to find it.

 

If you have one(which you may NOT as this car is pre-OBDII) it has to go from the exhaust manifold to the intake manifold. There will be a bung on the exhaust manifold and a steel tube leading to the intake. On some Mitsu engine you'll see them where the EGR valve does not attach to this steel tube. There is instead a passageway in the intake that leads to the EGR valve then the EGR opens and closes to put that nice sooty, tar and goop the EPA is so good for your engine right where it can clog up the works. Got to love the EPA for EGR.

 

Well, heard back from my Uncle, who rebuilt the head and says that on his other Montero that has the same engine, there is no egr.

Now my issue is that I'm failing CA emissions terribly and am assuming it can only be the catalytic converter.

 

It could be, but it doesn't have to be. If a manufacturer can pass emissions WITHOUT needing an EGR they don't use one. The one I was working on was OBDII and it had an EGR. Do you have a cat efficiency DTC? If you do you might need a cat. Remember cats need good cat food. If you feed your cat rich food what is going to happen? That's right, your cat will eventually get sick and die. It won't happen overnite. It takes place slowly. It's not the cats fault. It's your fault for feeding the cat rich food. If you get another cat that doesn't solve the problem. That cat is going to get sick too. You have to get rid of the rich cat food. Have you checked your fuel trims(LTFTs and STFTs)? I'd bet they rich. Do you have rich DTCs? If so why is fuel being added to make the cat food rich. You have to solve that problem before you replace the cat or you'll kill that cat too.

 

I know you mean well, but long-winded metaphors are really not going to help me right now. I need plain, concise English.

It doesn't use OBDII, it uses MUT II/III. My uncle (certified mitsu dealer master mechanic) suggested trying to change out the O2 sensors as a first option since it's the far cheaper one. If they're reading wrong or malfunctioning, it could keep the burn rich.

With that all being said, high NOx levels generally mean it's running too lean anyway, no? Either way, a faulty sensor could do either.

And is there any actual build-up/sludge cleaner that isn't just snake oil?
I want to cover all my bases before this thing gets re-smogged.

 

Seafoam.

Sea Foam Sales Company

 

I agree. Seafoam is the best. Your O2 sensors could be reading wrong(depending on age) or they MIGHT be telling you the truth. Maybe you really are rich. What are your fuel trims? Are you pulling fuel due to a rich condition. If you add propane do you see the STFTs spike RICH as your O2s see the propane. If they do they're reacting pretty quickly and you might actually have a RICH condition. Have you smoked this thing? What is RICH. You can be RICH two different ways. Too much fuel is RICH. Conversely, not enough air for the amount of fuel is also RICH. Air filter, injector stuck open, fuel pressure regulator, restriction in the air plenum passageway. The O2s is an easy way if they respond too slowly due to age, but it could be other things making you RICH.

 

I don't have access to thousand-dollar scanning tools so I really can't scan this stuff. If I could tell you all of that, I wouldn't be on a mitsubishi forum I googled.

I'm going to go with the O2 sensors first since nothing is setting off the check engine light and the issue is that it's burning too lean (high NOx), not rich.