Hey guys,
This one has been bugging me for a while.

Basic car info:

104,000 km
20,000 since rebuild

Every now and then (happening more and more lately), l will loose power at the top end of my rev range. At WOT, the revs struggle between 5K to a final maximum of 6.5K (sometimes only 6K).
I've done some searching on the forums and l'm down to the possibility of it being the coils and/or plugs, OR, the cat.
I'm actually leaning towards the cat, as there isn't that "blender" sound through out the rev range and the car doesn't miss fire or anything. Plus, the car runs like a dream on other days.

There is one strange sound though, when the car is at it's 6.5K max, the thing sounds like a chainsaw (I have the borla cat back fitted btw)! I don't know if it always sounds like that and l'm only noticing when l have the issue though...

Anyway, getting to my point, is there anyway l can narrow this down? How do l know if the cat is dead?

If it heaps, i can video tape the sound/revs.

Cheers.

 

You have to unbolt it. Look inside with flash light.

Also buy some extra bolts and nuts, they have a tendency to get stripped or be weled on.

 

sounds exactly like a bad cat except for the fact that it only happens sometimes. when mine went bad it was like that all the time.

 

i sort of have the same problem as you but i have no cat. if i seat on a traffic light after everything is soaked in heat it will turn off on me when i try to go. . . and the 6k issue also
74,000miles

 

Cheers guys, looks like l know what l'm doing this weekend.

Will report what l find.

 

Yes, sounds like a cat if the car is warmed up. But, if you are trying to do this when the car is cold, then it is a ECM limitation. There is a built in cut in the later ECM flash revisions.