cornerjunkie

I've had these codes pop up from time to time and finally ordered a PCV valve and intake manifold gaskets to see if that would do the trick. I haven't installed them yet, but today while driving home, I took a more 'spirited' route and noticed that the light came on. I also noticed the sulfur or "rotten egg" smell. I've noticed this a few times lately and have gone through multiple tanks of gas with the same issue.

My question is, can these codes be coming up due to defective/bad cats? I know these are emissions based codes and am hoping I alleviate them coming up with the minor (and inexpensive) fix of the gaskets, bolts, and PCV. What could be causing that smell? I know that smell can relate to bad cats, among other things.

Car has just over 75,xxx miles.

Merc63

Did you change the purge valve coming from the fuel tank? It's on the front right side. It allows gasoline fumes to be burned off, if it leaks you can get a lean code.

cornerjunkie

Nope, I didn't even consider that. I will look into getting one. I know that the cat's alone shouldn't be failing and that it is most likely due to some other cause, but I just can't find enough info to back up a claim that the PCV/manifold gaskets would cause that kind of damage. I guess if it is continually running lean at idle, it would cause the damage over time.

Dyno didn't show me running lean, which is why I'm a little suspicious.

jmueller

Pretty sure I had my o2 sensor replaced when P0171 came up for me.

Merc63

That purge valve is notorious for leaking. If that doesn't fix it, then I would do that bank 1 o2 sensor.

Like I said, the system is sensing too much oxygen in the exhaust, its either correct or the sensor is failing.