Hello!

So Ive had a Pacesetter Highflow cat on my 2000 EX for a while now. theres a lil power there and it sounds great.

however, oftentimes it has that weird sulfuer-rotten-eggs smell. (after im out driving like a maniac and running the car pretty hard) It doesnt make that smell when im just driving normal.

I read a thread here that said some cats just do that. however ive also heard that it could be because its running a lil rich and actually damaging the cat.

any ideas?

thanks

-a

 

If you have a stock fuel system etc, with no CEL's, I doubt you're running the car too rich. The reason you smell that "rotten-egg" scent is because you put a high flow cat in. The cat you have doesn't filter the toxins and that's what you are smelling. I have a resonated test pipe (ebay) type, and I smell the "rotten-egg" scent.

 

if he had a CEL would it be running rich? In turn would it be because of a fault primary O2 sensor?

 

ok cool. thanks mang

 

That's exactly what I was getting at. I have had three Civic's and when each one hit about 140,000 miles, I got a CEL for the secondary o2 sensor. I noticed worse gas mileage until the sensor was replaced.

 

I thought secondary O2 sensor was for just checking emissions and primary O2 sensor was for adjusting whatever to lean/richen engine.

 

I think there both used to make adjustments.

 

What???