Just a quick overview.

Over the last few years, I've had various codes related to fuel (generally rich in certain banks). I changed all O2's and they still came up so I gave up. My commutes were just 10 mins to the local train station so the car barely got driven. Now, my commute is 62kms each way and the car gets opened up a lot more on the highway. Recently gas would not fill in my car ($20 would take a good 15mins). My mechanic was able to push and free up the safety valve in the tank that blocked the fuel from going in.

After making 3 hwy return trips to and from work, my SES light has turned off on its own and the car is driving even better.

Anyone heard of this? The car has also been through various cycles (defog, heat, AC) all within that time as well.

 

Your cats are probably partially blocked the fact that you put new o2 sensors would make a huge difference on how the vq runs, the vq is designed to run better under load .(ac,defog, heater) ask your mechanic to check the precats. Do you have a fed spec or a cali spec?

 

I have no precats. Cattman headers. O2's were changed a year ago. Car hardly saw any load over the last many years until my new job recently.

 

Headers nice... well in that case it might be just ghostly codes due to the relatively small tolerance difference between the sensors and ecu..

 

Those 10 minute commutes were slowly killing your car. It barely got warmed up only to get shutoff and cooled down again. Combustion engines love the highway.