How many miles are too many to bother fixing (1 Viewer)

[White Stripe]

Ha, yeah...too much fiber...

So, this is neither the original nor OEM CAT...it is an aftermarket Magnaflow or something, and supposedly these aftermarket CATs are considerably more fragile than the OEM.

Since I've been trying to resolve vac/carb/ignition issues, I've been concerned about frying the CAT (operating under lean conditions). I've gotten the CAT really hot a couple times while I was fumbling around trying to figure out carb/ignition stuff...I've also been replacing gaskets/check valves on the EGR/ABV systems, and am about to change out the intake/exhaust manifold gasket (I can hear the strong tick of an exhaust leak in the engine bay), so I'm sure that plugging all those holes has built up additional pressure in the exhaust.

Problem is, I don't have a baseline measurement of expected pressure flow under correct operating conditions...maybe I'll try first loosening the front of the CAT and driving it to see if performance increases. I've already done the 'dollar bill' test at the tailpipe and passed, but from what I understand that gives information more on the condition of the valves/cylinders.

Also remember reading about using IR to measure heat signature before and after CAT and if there is a large temp difference, then most likely CAT's clogged. But don't have IR gun.

Anyway, I know this is slightly off topic, but actually might be helpful for the OP to rule out since a clogged CAT would cause power loss symptoms he is experiencing...

Pull the O2 sensor out and drive it around, if you have a ton more power you have a clogged Cat.

 

[White Stripe]

Do a good tune up on it like others have said. But this may be time to trade up to an 80 like mentioned if thats something that interests you.

 

[Chester]

Pulling the O2 sensor sounds like the winning method, but I don't think I have a problem with the cat. I pulled the cover off, and I'll reset the valves and solve the uppermost leak with a new gasket in the morning, then deal with some of the other leaks one at a time, this time from the top down. Still curious about an upper mileage limit though