apex seals and clogged cat
 

I've searched and haven't found the answer to this question: can a clogged catalytic converter blow the apex seals? There are no mods to the intake, yet, it has a down pipe and cat-back system. I haven't had time to do a compression check and I'm wondering if I need to.

No, but a clogged cat will rob you of any benefit the turbos bring to the game... @ 10 Psi of backpressure you're basically N.A. and anything above you're fighting a loosing battle... but that will just hurt your turbos in the long run, not the apex seals...

What kind of problems are you experiencing?

The problem started by a feeling like fuel starvation, then progressed to a constant miss at steady speeds, especially when the headlights were on, finally the computer showed error code 17. The exhaust smelled rich, and it would blacken the bumper pretty badly after 300 miles or so. O2 sensor didn't help (try the simple stuff first). Ruff idle most of the time, less noticeable when it was warmed up. While troubleshooting the problem, we noticed the Catalytic converter glowing "cherry red". We played with the spark plug wires and began to feel like the leading plug on one rotor was shot, all four showed excessive wear when removed. Changing the plugs helped the idle for a few minutes then it would begin to get rough again, and the cat still glowed. We remover the Cat, power much better, but it still feels rough at idle. A friend lost an apex seal and his car ran well at speed, but loped like a corvette with a cam at idle. I'm going to do a compression check to be sure, but our autox season begins Sunday (4-7) and I'm running out of time to get it back together. No trailer so it must be road 'legal' and I don't want to do any internal damage. Should I be concerned about the internals? Maybe it feels rough due to the open exhaust, it sure sound good thou. I can get a cat and install it in time I'm worried about what other damage a clogged cat can cause.

Clogged Cat
 

I have been a drive-ability specialist for 20 years and with a restricted cat converter its like towing a heavy load thats on fire. The engine will have to work much harder to make power and it easily could damage the unit. One of the first things is it will not be able to exhaust "heat" created and will likely overheat much easier. The fact the cat is red means its is seeing far too much HC. The fuel mixture sounds clearly rich, thus extra fuel to turn the cat 'red', on fire. I would not drive the car until you nailed down the cause and repaired it.

how many miles can your "typically" get out of the stock cat before it gets clogged

Mine was clogged when i bought the car at 95,000 miles. The stock cat may help you pass emissions but it is definitely one of the most restricting parts of the car. (the pre-cat is also very restricting)

It's not your engine. Check your coils and your plug wires (corrossion). Sounds electrical...

I think we may have found it. The compression was fine for an engine with 70,000 miles. but a finger test of the vacume lines showed no vacume on some lines. We have found a line, neer the turbo solenoid (I think). It appears to have been pinched, and has slowly worn thru and at this time has deterorated to a big hole. At this time I don't know exactly which line it is, nor what is provides vacume to, so I'll post back when I have more specific info. Right now I need to get back, I still hope to run tomorrow. Oh, by the way, Mrrx-7, One of the coils was a little weak, I'll be getting replacements soon, along with a vacume-line job. thanks.