Help me solve a problem- exhaust, cat?

hey guys, been having this problem for a while now. I've researched into it, but want to get others' opinions.

To make it simple I made a video, but I'll explain:



Sit in idle (park) for a little bit, gradually the rpm start to fluctuate, sounds like the engine is dying repeatedly. Upon acceleration, engine sputters, bit of delay between pressing pedal and getting power.

If I floor it (in drive) same thing happens, but it seems to help get through the problem (I suspect it to be an air flow problem, it forces air out and recovers).

I have a very good feeling, after research, that I need to change out my drivers side cat. It sounds like I'm dragging chains down the road, right underneath me, when I'm able to hear it while driving.

I have properly cleaned the MAF, changed spark plugs and coils (needed to be done anyway) in hopes of correcting the problem- but it still persists.

I have had codes pulled- you'll see my CEL on - came up as fuel is being burned "too lean" if I remember correctly. Oreilly's guy says that's usually a problem with air flow and usually comes down to the catalytic converter.

So I'm just looking for other advice, before I go and pay for a problem to be diagnosed that I might've already diagnosed.

 

Did you get a P0171 "System too lean" code? I had that a couple months ago that persisted for awhile, it's usually due to a dirty MAF or vacuum leak somewhere (mine turned out to be a vacuum leak from an unplugged port on the back of my supercharger). An exhaust/cat issue is usually less likely with this code but it sounds like that might be what your's is. A clogged fuel filter can also set off a lean code and can cause your engine to sputter when it struggles to get fuel, something else to maybe consider. It's a cheap DIY fix anyway.

 

I believe that's the code I got. It was a while back, don't really remember the exact code, but it matches the description.

I've thought about the fuel filter as well, which could also be an issue in the problem, but I've never heard of a fuel filter sounding like chains dragging while driving. Could be a combination of the filter and cat. I need to set aside the time to actually clean my throttle as well, might help.

 

BUMPITY BUMP BUMP BUMP

 

It would depend on which of the 4 O2 sensors gave you that CEL. If it was the front set that is in front of the exhaust manifold cats, then it shouldn't be a flow problem with the cat. If it came from the rear, then it's possible.