What does"Catalyst system Efficiency Below Threshold" mean?
BMW Tech
Joined: Oct 2002
Posts: 514
Likes: 0
From: Suffolk County, NY
Originally Posted by 98CoupeV6
Sounds more like a loose heat shield. If your cat is bad you'd get awful nitrous oxide smell inside the car when accelerating up hills. I know because mine went bad at 150k and I didnt change it until 210k 
h:
h:No it wasnt the heat shield because i removed the whole shield and it still rattled. then my exhaust got ripped off(it was a greddy evo that was 4 years old) i unbolted it and check the inside of the cat and the honeycomb material was completely loose.
it would only smell inside the car if the car had a whole in it otherwise it would just smell like sulfur from the rear and it would blw black smoke once in a while.
the funny thing is that mine doesnt smell and doesnt blow black smoke. and like i said that my cel hasnt come on in 40k.
Senior Member
Joined: Oct 2004
Posts: 444
Likes: 0
From: Atlanta Area, GA
Done a new O2 sensor anytime in recent past???
Honda wants $7XX.XX for a new cat for my 95. I asked for s***s and giggles. Or I can get a Magnaflow (?) for like $75.00 or so.
The cat. is not a huge deal. You just don't want it to catch on fire, at least not while you're in the car.
Honda wants $7XX.XX for a new cat for my 95. I asked for s***s and giggles. Or I can get a Magnaflow (?) for like $75.00 or so.
The cat. is not a huge deal. You just don't want it to catch on fire, at least not while you're in the car.