Hello,

I usually can find the answers to my questions but this time I'm stumped. Last night I was merging onto the highway and accelerated to 4000 rpm, As i was accelerating i noticed the engine was getting louder between the 3500-4000 range. After 4000rpm the engine was very loud and i notice a substantial power loss. To give you an idea, the engine sounds like it was revving at 10000rpm. I can surpass 4000 but it takes much longer than before.

If i keep the rpm range under 4000 the car rides fine, sound is a little louder but not substantial. Power is fine as well, i don't notice a loss in acceleration. No modifications have been done for years, all the levels are within normal range. Anyone have any ideas?

I have noticed latley that my catalytic converter has been rattling like crazy, maybe something got loose?


Thanks

 

an exhaust leak is possible, but it sounds like your IAB's are getting stuck closed.

 

Thanks for the reply, I will take a look and see if the IAB is stuck. I also forgot to mention that my check engine light is NOT on, which is making this very difficult to diagnose.

 

clogged cat for sure, it blocks exhaust flow and absolutely KILLS your power. Take off the cat, dump out the broken stuff and put it back or just replace with a high-flow (or test pipe but those are retarded)

 

I thought about taking the cat out to see if anything was blocking the pipe. I may just end up hollowing it out if possible until i get the HF cat. Hopefully that is the solution, the only hard part would be trying to loosen the bolts off!

 

When i put my HF cat on i had to cut off the old bolts and get 6 new ones.

 

make sure you grab some PB blaster and soak the bolts in them for a little before you try getting them off..
should help.

 

Melted a cat and it did the same

 

Well I was able to get the catalytic converter out. When i took out the catalytic converter and i could see a chunk probably 3x3 that had rotated and was causing the blockage. I hollowed it out, went for a drive and the problem was gone. Now i just need to get a high flow cat. Thanks for the help.

 

Good 2 hear

 

Good to hear you found the problem. I've been there myself. Mr Shakespeare describes a clogged cat the best... "All the sound and fury, signifying nothing..."

I have a 2.5" Magnaflow metal core race converter BNIB that I decided not to use. PM me if you're interested.