95 GTP Catalytic Converter Question

I would be surprised if it were true that there is no legal ramification to removing your cat, even in the case of an OBDI vehicle. Perhaps the truth is that, in your province, a safety/emission inspection isn't required. That doesn't necessarily make it legal to modify your emissions system.

If the cat is actually plugged (what are the 'classic symptoms of a bad cat', anyway?) it most likely got plugged due to a meltdown from poor fuel management conditions. This root cause will need to be addressed to achieve a proper running car regardless of the converter situation.

Finally, please explain how low backpressure (the kind realized from removing a converter) negatively affects low end torque? I know, I should have asked 'some', since 'some say that'... :)

Toyota MDT in MO

I've looked into emissions regulations for Saskatchewan, and it seems that you cannot remove a working catalytic converter nor replace any catalytic converter with a used one. However, once one is worn out, it can be removed and does not need to be replaced. I'm not sure why the law is like this, but it is.

As for the symptoms, I have significant lost power, rattling coming from the cat, poor idling, an 'air sucking' sound coming at WOT, and higher than normal average engine temperature. From what I've read it seems that the catalytic converter is worn out.

and about low backpressure causing loss of low end torque - I'd like to hear a good explanation too, I don't know where the numerous people got this information from.

Can anybody else throw in their opinions?

There's a possibility of multiple problems as I stated earlier, but one of them could be that your cam gears are out of time. These engines are hard to set up the gears on during a timing belt/ front cover service. There is no keyway for the cam gears to line up exactly on their respective cams, so they can be put on any old way. A few "teeth" off and you suffer bizarre drivability problems, the most likely being a loss of power. Also, if a cam gear *was* to slip while driving, it would slip in the retarded direction - really causing a loss of power.

Ofcourse you could remove the headpipe at the most convenient pre cat location and drive the car for an A/B comparison before condemning the cat.

Toyota MDT in MO

I took it to Midas yesterday and the catalytic converter was indeed shot. However, they replaced it with a glasspack instead of a straightpipe since a straightpipe would be a lot noisier. I regained a lot of power that I had lost before, but it sounded like there was a lot of air escaping when I would accelerate. I took it back to them and they said that because of the glasspack there is more air flowing, and that the sound I hear is this increased air flow and a result of the different sound from the glasspack, not a leak from anything. I, on the otherhand, am a little skeptical. Does their claim hold any merit or should I start looking for a leak underneath?