Recently noticed a distinct sulphur smell coming from my exhaust pipe when my Hybrid Toyota Camry 2007 is idling/driving. I’m not getting any check engine light, not a noticeable decline in acceleration and fuel economy could be slightly worse but not enough to be sure.
Did a quick scan after a short drive on a personal scanner and it was coming back that my second down stream oxygen sensor was dead in the water.
Put some premium gas in my car just to see if that made a difference. Went to a mechanic shortly after to get a proper scan and see about a new cat and sensor.
That scan came back that everything was fine and both sensors were working and not showing any problems. The mechanic too a look underneath and advised everything looked fine. He was convinced my issue is not the cat but I’m not.
Are there any other sensors that monitor the cat performance that would go off if there was issue and my oxygen sensor is dead?
The downstream sensor is supposed to look like it’s dead in the water. (See here).
That said, the #1 reason for the sulfur smell is a bad cat. But see Tester’s link.
The gasoline octane is irrelevant. “Premium” is mislabeled. It’s not somehow “cleaner” or “better.” It just higher octane and resists combustion more than lower octanes and is largely relevant only with high-compression engines. Your Camry just needs 87 octane.
There are no other sensors that monitor cat performance. There are codes that can indicate problems with the downstream sensor. But none of that is relevant to the sulfur smell.
If you can post some graphs of your O2 sensors live data (up and down stream, that might show something).
You are willing to spend $1,000 for better smelling exhaust? Probably won’t help.
Increased exhaust odor in cooler weather is a common occurrence. The winter fuel in my area causes a foul smell from the exhaust, more noticeable in older vehicles.
Nevada beat me to it. There can be a variation in the sulfur content from one brand of gas to another, so switching brands might yield an improvement for the OP.
That being said, some cars (the early Ford Taurus models come to mind) seemed to emit more of a sulfur smell from the exhaust–even when brand-new–than other models. However, I don’t think that this problem applies to more recently-made vehicles.
I strongly recommend that the OP begin a bit of experimenting with different brands of gasoline.
