New exhaust part installed - burning smell since then. Normal?

[drypowder]

Had an exhaust leak in the downpipe/'A' pipe (pipe connecting exhaust manifold to catalytic converter), and I had an exhaust shop replace it with a Walker Exhaust aftermarket downpipe in my Accord. Ever since then (~550 miles), I've been noticing a burning smell. I thought it might be the manufacturer sticker that wasn't removed (kinda large sticker, maybe 6" x 4") being smoked off by the high temps of an exhaust. But a quick look under the car (as good a look as I could get without jacking up the car and getting underneath) shows the sticker doesn't look like it's burning.

So maybe this is normal when exhaust parts break in? Or the adhesive of the sticker being smoked off (though if this were the case, I'd imagine the sticker itself would get burned up)? Or maybe the gasket goo they put between the flanges (in addition to the actual gaskets I provided)?

 

[Beef15]

Sticker hasn't cooked off in 550mi?
Probably it. And any oil or goo that got on stuff since apparently your exhaust is not building much heat.

Check for something that maybe got disturbed and is now touching or near and as long as there's none of that I wouldn't worry about it.

 

[drypowder]

Sticker hasn't cooked off in 550mi?

Nope. From what I could see without getting right under it, the sticker is completely intact. I was surprised too; like you I figured the downpipe would be the hottest part of the exhaust since it's directly connected to the exhaust manifold, and that the heat would cook that sticker right off.

Had this done while I was up in NY. Took the 500 mile ride down here and when I got out of the car, the first thing I noticed was the burning smell.

It has gotten slightly better in recent days, but these are just short local trips, where the exhaust probably isn't getting nearly as hot as on the 500 mile trip.

 

[Scsmith42]

Walker used to coat their exhaust pipes with a clear coat, that would burn off. However, a 500 mile road trip should have burned everything off by the end of the trip.

Check to see if the exhaust shop left a heat guard off. The smell could be coming from someplace else, or you could have an oil leak that is seeping onto the pipe.

 

[drypowder]

Had a chance to get under the car and get a good look. I think the sticker is being very slowly cooked off. The downpipe's heat shield is actually the outer pipe - i.e., the actual exhaust pipe is inside the outer pipe/heat shield. Using a heat gun, after a short drive with the engine idling, I measured the outer pipe at ~250*F. That would explain why that sticker is still mostly intact - it's just not getting hot enough. It would also explain why the burning smell was stronger right after I stopped the car after that 500 mile drive trip than it has been in subsequent short trips.

The little bits of sticker I could peel off were browned on the backside. Tried using some Goof Off, but it wasn't particularly effective (i.e., it was going to take too long).

The shop did a good job on the installation of the downpipe and it's not touching anything. And I don't think the smell was burning oil - I never noticed this particular burning odor until right after the pipe replacement.

I'll just leave it for now and hope between wet/dry cycling (as water gets splashed on there when driving in rain) and the slow cooking, it will eventually all go away. If not, maybe when the weather is warmer, I'll get under there and get that sticker off with some Goof Off and some elbow grease. Until then, I'll just keep the air on recirculate.

Lesson learned - remove any stickers from exhaust parts before installation.