I did MAF, O2 sensors, purge valve, upper intake gasket and checked my valley pan all after reading the forums about these codes. I almost sold the truck I was so frustrated when they just kept coming back after a month of trying to figure it out. If you have the purge valve already I would just put it on so its one less thing to worry about in the future.

 

Ok cool, thanks, that's good to know. I've replaced both front O2 sensors with Bosch models from Advance Auto Parts last month, and the new MAF should be here in a few days.

I will be sure to look at those upper intake and valley pan gaskets also, almost forgot about those. The guy I bought this Disco from used to be a mechanic at Mercedes and he basically rebuilt the engine, and after owning it a little over a year I've barely had to do anything since he did such a good job--apart from changing the oil of course.

However, a couple months ago I had to replace the crank position sensor (which was a real bitch to get to, but not a terrible job) and now this Check Engine light is like a little yellow demon that keeps coming back, but hopefully we can figure it out.

Going to do the purge valve install this weekend and will report back.