It is true, your cat can fail and still pass with normal emission readings.
Even a quick look at the cat isn't good enough, I had to shine a light into mine and noticed it was backed up further in the first bank (before the o2 sensor), and there was a few small pieces loose between the two banks that broke off or whatever.
I'm just saying, it'll require a closer look to completely rule it out.

In regards to those bolts being seized on the flange, don't worry about it. If you can get the nuts off the one side, just leave the bolts in the other side. It takes some wrestling, but the exhaust hangers allow enough room to move the exhaust back just far enough to separate the flange with the bolts still on (w/o nuts obviously)
I then took some penetrating oil and let sit around the bolts for an hour. I came back and gave them a few light taps and presto...

If the cat is backed up even a little, I'd gut it or throw in a mid-pipe. The stock cat is already quite restrictive.

SSV is still a concern, because it can come and go as well.
I think when you shut off the engine the actuator should cycle once, although I've caught word that not all of our cars do this... Not sure what's up with that, but might be worth a look-see...

Thanks Little!

I'm starting to think that I should just go and rip the damn SSV out to clean it no matter what I find in my catalyst. I have gotten oil in the accordian pipe and even found it had stained my air filter somewhat. I'd be suprised not to find any gunk from the SSV.

Found out my problem today,disconnected the MAF sensor and went for a drive....stalled everytime but was otherwise as smooth as butter! Ordered a new one today off eBay.Nearly took the SSV out but thought I'd try the mag first.Only problem being disconnecting the MAF also disabled TCS so was a little wild to drive :-)

I am pretty sure you were in limp mode

Bonesy-Yeah, I think that would leave the car in limp mode, not certain, but I think stinksause is correct...

Kilppa-- I agree with you, if you have oil in the intake, it'd be a good lead to a faulty SSV. Regardless if it is what's at fault or not, it's still a good preventive measure to take.
Plus when things are said and done, you'll have peace of mind with it.
I'd suggest installing an oil catch can afterwards to prevent overfilling the oil in the future (usually the cause)

Let us know...

I tested the SSV valve with a vacuum pump and it opens nice and easy around 6-7 in.hg. So what's next, solenoid? Damn that UIM looks like trouble to remove! :eek:

Personally, I have not heard of the solenoid going bad ...

UIM isn't too bad ... just be careful with all the vacuum tubes

LIM is next to impossible to get off with motor still in the car

I still say cat

Okay, so is the pressure switch any more likely culprit?
I already tried to remove the UIM once, but couldn't do it since couple of bolts were in seemingly impossible location. The bolts for the port most furthest to the firewall.

My cat gets looked at by a garage next wednesday. Basically I am hoping it'll be the cat. I don't look forward taking out the SSV valve for cleaning, unsure if it fixes anything. It would take me atleast one day to do it, mayby two if I need more tools. This is my only car so downtime gets really annoying.

if you take out the motor mounts (3 bolts each) you can lower the engine almost 2 inches

Solenoid probably isn't very likely the issue, however absolutely worth checking... Nothing the SSV relies on should be "assumed functional"
If the actuator is working at the correct vac. and it doesn't lose the vac, then it's starting to point at the cat... But again, don't assume you can move past related components.

I say just put a mid-pipe on, if it doesn't clear up, I'd then take it out on a fire-breathing run, the kind that will throw the needle right off the tach... Maybe it'll clear up some potential build up. If not, then atleast you can shoot flames at people driving too close, or better yet, get the girls walking down the street to scream from the gunshot. :)

Yeah, the SSV holds the vacuum nicely.

If the cat is frakked, I'll just gut it. Everybody has to do their smog tests here, but rotaries are exempt from it, for whatever reason. I don't mind.:naughty:
So you have to have a cat, but they don't measure the readings. So basically as long as it SEEMS like you have a cat, it is all good.

I just hope I don't trip the CEL.

what year is your car?

2004. What do you have in mind?

You may not get the CEL for midpipe ... Some 04s don't

My 04' 6spd threw the CEL within maybe 200 miles without the cat, if that.
If it really bothers you, there are a few options of cheating the o2 sensor that trips the CEL.
I'm not certain which is the best route yet, as I'm still undecided myself.
This is not advice, just information... (legal purposes)

1. A spark plug fouler installed where the o2 sensor should go, then screwing the o2 sensor into the fouler will leave it slightly out of direct path of the exhaust gases. This simulates an exhaust restricting the gases with a cat.

2. Tac weld in a little baffle that will sit in the path to the sensor.

3. The one I will most likely go with... Order what's called a Mini-Cat, which is basically what it says... It's a little fitting that contains a mini filter or mini catalyst material, which goes into the exhaust pipe, then goes to your sensor on the other end, thus simulating an actual cat installed.

The CEL doesn't bother me, but I don't like people asking me about it.

I'm not really worried about the CEL in itself. It's just that if I decide to sell the car one day, it shouldn't be there and I'll probably end up having to get a new cat then.

Word

The cat was examined and the mechanic said it looks normal. He took a picture of it for me. It looks golden colored like it is supposed to, only has a little dark smudge in the center with a diameter of mayby half an inch. BUT... the honeycomb also has a hairline fracture going from the center to both sides, like it would be split in half! It is a really thin line, but clearly visible. Now... This being the case, is it possible that the rear honeycomb is clogged?
Any way of checking this out without bashing the front cat into pieces?

Yes, its possible, but not very likely... You can use a small mirror to look inside through the o2 sensor hole ... or a camera ... but that is expensive, I think plumbers may have access to small cameras like that?

So my best bet is biting the bullet and cleaning the SSV?

I do smell something horrid after a spirited drive, doesn't that point out to the cat? Also, it seems to be worse when the car is cold or when driven gently, but seems gets somewhat better when I have been driving the piss out of it a little. :dunno:

Does anyone have any input on this? I have to leave for a 300 mile road trip tomorrow and I'd still have time to gut my cat if it still is a likely suspect, to prevent possible engine damage.

Heeeelp. :)

I would say your engine is safe ... SSV seems like the culprit here after all

Thanks for the encouragement. :)
When I get back, I'll check the plugs just in case. I know they are only 3500 miles old, but never hurts to check. After that I'll take my time to rip out and clean the SSV.

If anybody has any insight on this whole matter, please speak your mind.

So I took out the plugs and it would seem that on one the tips were black, so it isn't igniting properly. I ordered new plugs to switch them all out and a new coil for the blackened one, to make sure it isn't caused by that.
Is this a likely solution to my problem?
What could cause this to happen to a brand new plug or coil?

Flooding ... but not to just one ... the coil is weird ... you got me on that one.

I tossed the OEM coils for BHR long ago