Swap the front o2 s from one side to the other and see if your problem switches sides. If so you need a new sensor.

 

I was thinking about the air intake (K&N). The actual engine intake has never come off.

 

Would a bad front O2 sensor effect the rear one? I'll give it a try.

 

Bank one should be the drivers side. Rear o2 monitors cat performance and front o2 monitors engine performance.
Sounds like intake/exhaust leak assuming o2 is functioning properly.

 

Okay, I see now. If the front one is messed up and telling the engine to do something wrong, it will effect the rear.

Thanks.

 

You damn Navy guys......

 

Yeah, I'm not even a Nuke and I'm Nukin' it!

 

What rate are you? You must be an engineer. CTT here.

 

Another way to check the intake manifold, is to turn the truck on...grab a water bottle, and spray towards the intake manifold (not the K&N) . Make sure to spray very very little at a time incase you have a leak. If you have one, engine will stumble a little once you hit it with the water. DO NOT OVER SPRAY...keep it short and sparatic.

 

I'll kick you in the shins for that! I'm a FC