Sulfur smell from 2000 Insight

[bikeracer]

There are a couple of posts in the 2010 insight section in InsightCentral, but very little about the sulfur smell in their gen 1 that wasn't speculation about an overheating CVT.

Mine is a 2000 MT with 111k miles. I was driving up a long hill at night. A friend was following. He told me later that my car smelled like sulfur. We didn't encounter any other cars on the road on that hill, so I hesitate to doubt him. He was also alone in his car and therefore had nothing to hide by pinning the sulfur smell on my car.

I have an 80% lower grill block, a IMA bypass switch which works off of the clutch circuit, and the ScanGauge was reading between 197 and 202f. Nothing out of the ordinary for hill climbing.

I've never smelled the smell myself.

Any thoughts? I do have a P0420 code which is an 02 sensor issue. I think it's the upper 02, but it might be the one in the cat.

Thanks
Patrick

[RobertSmalls]

P0420 is "Catalyst Performance Below Threshold", and bad cats often smell like sulfur.

[Johnny Mullet]

I agree with Robert. P0420 usually means the cat is not doing it's job anymore.

[Old Mechanic]

I think Robert pegged it.

regards
Mech

[jamesqf]

Mine has always had a bit of a sulfur smell on long climbs, where I'm doing nearly full throttle on a 6-7% grade. (This is e.g. crossing the Sierra, where the climb is from sea level to 8000 ft.) Haven't had any real problem with codes. I did get the P0420 (IIRC) for a while, but it was fixed by an ECU upgrade from Honda (under warranty).

[bikeracer]

Update: I replaced the upper o2 sensor this morning and both codes (0420 and 1164) did not come back in the 4 mile commute. The old o2 sensor was black with soot. It was replaced with a used but confirmed-good Insight sensor from a salve (thanks Brent Springer). Not only did this chase the codes away (for the morning's commute), but my engine idle is now 200 rmp's lower, hovering now around 950 where before, 1150. Can't speak for the sulfur smell, but I believe progress has been made.

Question: could the blackened o2 sensor be an indicator of worn spark plugs? I do notice uneven acceleration/power that could almost be described as hesitation at low rpms. I've not checked the plugs, but they say 105k (or 7 years) is the time to replace them. I'm 3 years and 5k miles due.

[Old Mechanic]

The bad O2 sensor was probably the cause of the black plugs since the mixture control feedback depends on the sensor.

Plugs certainly would not hurt so close to the recommended interval, but I think you had a bad sensor.

I have seen plugs go 90k on a 30 k recommended replacement interval without any check engine light. Not recommending that you do not replace them.

regards
Mech

[luvit]

i owned a 2004 civic hybrid. sulfer smell would happen bout once every 300 miles.
if i kept the car recycling it's own air i wouldn't notice, but if i didn;t remember to do that, it was embarrassing.

ya see, if you have another passenger in the vehicle they think you passed gas. and i didn;t want that to happen.. even if the passenger said nothing, because if i explain it, then i sound guilty...