ltk_1997

I'm getting a rattling/rubbing sort of noise from the front end of my Acura. It occurs when in gear, especially uphill or when getting up to speed and goes away as soon as I push the clutch or let off the gas. Also it seems to be worse when I hit bumps.

2000 Acura 1.6EL
D16Y8 engine
5 speed manual transmission
168k miles

Video of the sound:


I recently had my tires switched to all-seasons, replaced the brake pads and spark plugs, and did an oil/filter change.

I'm not sure if it's related, but the CEL came on a while ago with the code P0420, it seems to have less power than it used to.

Thanks in advance!

TomCat39

I couldn't hear anything in the video.

I also don't have high quality speakers on my laptop at the moment only the harmon kardon laptop stereo speakers. They are good but they are small, might not reproduce the sound well enough for my aging ears.

ltk_1997

I stuck my phone in the engine compartment and took another video, hopefully it will be a bit clearer:

The sounds starts at 0:39 and stops at 0:42 when I shift. Then 0:53 to 0:58 and again about 1:22 to 1:30.

Again, only seems to happen when the car hits high RPM while accelerating, I don't hear it at all while down shifting and it stops as soon as I take my foot off the gas.

Chance EG

P0420 is a code for the catalytic converter. That rattling noise is possibly something that's stuck/caught inside the cat, which is restricting exhaust flow and therefore robbing power, throwing the CEL.

That's where my money is. That's kinda what the sound in the video sounds like for me too. Also, just side note, you won't necessarily hear the noise if you just rev the car in neutral. Since there's no load on the engine it won't be producing as much exhaust or have the same vibration/resonance through the exhaust. Could also explain why you're only hearing it at certain RPM/speed, or when going up a hill because there's a certain load on the engine.

TL;DR - My money is on the cat.

ltk_1997

Thanks Chance,

I finally got a chance to pull my catalytic converter today (and the whole tailpipe since the cat bolts are pretty much welded on). It looks okay from the manifold end, but I'm just going to replace it anyways since it's throwing that P0420 code.

I took it for a short test drive, the car runs way better with the whole section off. Tons of power (and sounds like something out of The Fast and the Furious). As soon as I get paid I'll be ordering a cat from Rockauto and then grinding the old bolts off and replacing it.

fragmare

I knew it was a clogged cat from the first "chug" @ :39 in your 2nd video. That sound should be trademarked haha

ltk_1997

So I was looking at catalytic converters earlier, and found out that some people replace them with "test pipes". Is there any downside to doing this? I do not have emissions testing where I live, so as far as I can tell the only real downside is that I'll have a check engine light from my downstream o2 sensor? I'm looking at this one: For 88-00 Civic 94-01 Acura Integra Direct Fit S/S High Flow Exhaust Test Pipe eBay.

ltk_1997

Decided against the test pipe and just ordered a replacement cat from Rockauto. Installed it today, cleared the codes and it runs great again! Will update it if I run into any further issues, but it's looking good so far.

TomCat39

You can use a defouler (usually a 90 degree type is most suitable) to stop the 2nd o2 error.

The downside to the test pipe is smell. Even in my 2007 Coupe Si with no cat, I get wiffs of great smelling exhaust when I pull up to a stop light.

My 95 hatchback was even worse with a test pipe. Seems the air pillow that forms behind the hatchback traps that exhaust and then that pocket of air just flows forward over the car when the car stops.

My solution was a high flow cat. That worked well to get rid of the smells while reducing power the least possible for having a cat.