Rep Power: 312

Hiya, thanks in advance for any suggestions.

I changed my head gasket in the spring, ever since then I've had some sort of an exhaust leak. I can hear a faint trace of it when the car is idling, but i can really hear it when I'm going through a drive through (like mcDs or tim hortons) when the sound is echoing off the walls back into the cabin. I just sat there with the car idling revving up and down for 20 minutes and I can't find it at all. I replaced the manifold gasket both on the block and downpipe to eliminate those spots, and I can't feel any exhaust flowing out of anywhere. The other major symptom is when I come to a stop with my heat on (with circ. off) it smells like exhaust really bad inside the cabin, but when I'm moving I can't smell it at all. So now I'm driving with recirc on all the time because it's getting pretty bad.

I'm baffled, I'm gonna go outside and get the wife to put her hand over the exhaust to see if I can see a leak. I'm worried it might be the catalytic converter, it's all covered up so it would be hard to see a leak.

Hopefully someone can give me some info here as to whats going on! Thanks.

Oh yea, I have to take the car for an emission test and I don't think it will pass with this going on.

 
Rep Power: 233

There are gaskets between the downpipe and cat, between the cat and resonator, and between the resonator and muffler. While your there you might as well pull the cat and look it over for leaks too. Also, if you can hear anything rattling around in the cat then it's fading and you'll need a new one pretty soon.

 
Rep Power: 312

Damn. There is a ton of vibration from the downpipeto the cat area it seems more than normal. It's far too cold here for me to be pulling the cat off and I don't have a garage to do it in. It will have to wait until the spring. The exhaust seems to flow okay, I got the wife to hold her hand over the exhaust while I watched for leaks and I didn't see anything. So now I'm wondering if I'm hearing the rattle of the cat you speak of. It does sound hella like an exhaust leak though.

 
Rep Power: 233

Just run out there with a rubber mallet (metal hammer is ok if your very careful) and tap the cat LIGHTLY. You can lay beside the car and reach just fine (unless your a midget, er...small person). If it rattles it's bad or going bad.

edit: I just realized your in Canada. So much for laying beside the car in a coupe feet of snow. lol. Find a dry piece of pavement to do the above in, like a parking garage.

 
Rep Power: 312

Well, we have no snow here just yet. So that's still an option. I'll have to remove the shield around the cat to do it though. I'll try it out. Definitely sounds like its coming from the Cat area. Thanks a bunch, I'd rep ya but I already did somewhere else

 
Rep Power: 312

I just priced out a cat, 867 dollars shipped to Canada from South Bay Honda I hope its something else... but we will see. I'm going to wait this one out until i get some cat-related symptoms

 
Rep Power: 312

Anyone have any experience with Random Technologies catalytic converters? If mine is truly fubared then I may have found a reason to upgrade my exhaust, it says that it meeds California standards but I'm skeptical as we here in Canada need to pass an emissions test:

http://www.dezod.com/pd_random_technology_hiflow.cfm