It says left o2 sensor. Both were replaced last fall. Would a small exhaust manifold leak on that side make it go bad? I also hooked up a coolant line wrong at first when I did the tb bypass and had coolant going in the intake on that side. But I was getting a code before that happened. The only time it throws the code is when its hot out and I'm sitting in traffic.

 

I think if I just take it out and clean it and make sure theres a good connection it might be alright.

 

You might want to make sure that you don't have any burnt or damaged o2 sensor wires as well.

 

I got the same code on o2s that had less then 50 miles on them. I swapped sides and things where fine. No more problems after that.

You might have a connection not securely fastened. But one thing I would worry about is the coolant in the intake. That can damage your o2s. But you would think both sides would have been effected.

Take them out and wap them around and see if the code follows the sensor. Also scan and see if the o2s are goingup and and down during idle from aroud 100 mv to 800-900 mv. Up and down etc,,. If they are not, then they are trashed and you need new ones. I never had any luck cleaning mine with a wire brush or anything.

A small exhaust leak would not cuase the o2 to fial but you would get a flase rading on that side. A leak before it will pull air in and it will show lean and try to richen your car up.

Jason