Today my car threw a code 67. I know it's the catalyst performing below threshhold or something. I also searched and know there's no problem driving it like this. What I was wondering was I read on here somewhere once this problem could be because of humidity & temperature. The light came on today when I was driving the GSR in fog for the first time. I just want to know if this is a viable reason for my problem.

 

Fog? Maybe those cats and O2 sensors do some weird things. I'd suggest clearing the code and seeing if it comes back. If it does use Chevron Regan fuel treatment for a tank full, then reset the code. If it still won't leave then either repalce the cat, O2 sensor (which could be the problem) or get an O2 simulator and be done with it. BTW how many miles do you have on your car?

 

the odometer reads like 68,000; but it's got a new engine in it, so it's at about 8,000 miles.

 

yeah I'd clear the code and see if it comes back after that. Do that before you pursue any other maintenence.

 

When I reset the ecu, and started the car, the cel came right on and didn't turn off. But today, someone almost hit me on the freeway, and when I swerved to miss him, I ended up skidding. Luckily, I wasn't hit. When I turned the car on again, the cel was flashing, and when I checked it, it came up as code 3 (MAP sensor), now the code 67 doesn't even come up.