I think I keep reading that the MP5 has 2 cats, if this true or are they talking about a different car?

 

all proteges (3rd gen) have 2 cats..

a pre-cat on the exhaust manifold and a secondary cat on the second pipe. Only the precat is used by the computer...the second cat is a back-up / fail0safe for the sniffer.

 

Gee I wish they had that on my Jeep I can't get this thing past emissions. I'm about ready to register it with my uncle, he doesn't have emission testing where he lives.

 

just move to alabama....I never knew what a "sniffer" was until I drove through Georgia one day during testing.

 

My uncle live in the same stat that I do. He just happens to live on the OTHER side of the bay. They don't have the testing because the population count is lower there than it is here. BS!

 

not ALL 3rd gens have 2 cats...you keep forgetting about us lowly 1.6er's Matty

 

we 1.6l guys have 2 cats also, on the lower end of the exhaust manifold you'll see it. its right before the downstream 02 sensor, the exhaust that i have removes the secondary cat and retains the resonator

 

I didn't think about the 1.6ers....but it looks as though I was right anyway!

 

read Edwin Mann's Protege FAQ, the 1.6L has one cat, unless you have the California Emissions model....not to mention I can look at my exhaust manifold right now and there is certainly not another cat there..just the one before my aftermarket exhaust, that's it.

 

huh, I sit corrected!

 

1.8 also only has one cat, unless a ULEV equipped vehicle.

 

i'm not trying to argue or anything, but then what is the downstream 02 sensor doing if there is no cat before it, the whole point of it is to read if the cat is working, if i'm wrong dont flame me, just trying to get the correct info.

 

just looked at my shop manuals exhaust diagram, both the 1.6l and 1.8l show two TWC (three way catalytic converter) the one on the manifold is a WU (Warm Up) TWC and the one before the resonator is a regular TWC. it is between the exhaust manifold and the down pipe, looks like a plain old cylinder with a heat shield. again if i'm wrong, then tell me

 

typically what you have is an o2 sensor in one of the runners before the pre-cat. This reads the content of the gas BEFORE the cat. After the Pre-cat there is another sensor that is used to determine how clean the gas got from the first cat/ The second cat is just a precaution....If you elminate the first cat you can easily relocate your second o2 sensor to behind the second cat and everything will be fine.

 

exactly, so that would prove that there is a WUTWC on the exhaust manifold. which would mean that there are 2 cats on the 1.6L.