looks a bit pricey for me ill take a refurbished one for $100

 

I'd be really surprised if it had anything to do with running no muffler. Check the MAF sensor again, those things are extremely delicate. Ive been running my truck for about a year now, just cut the stock one off, ran some pipe and dumped it and i've had to problems at all.

 

i just got the true duals put on yesterday. it sounds sweet and just as i thought that fixed the problem i was driving it and the CEL poped up so looks like im getting a new MAF sensor

 

clean the maf with electric parts cleaner and q tips. clean the mass air sensor with electric parts cleaner. I had the same code and did the above and code is gone. I also ran the truck with the filter off and sprayed some tb cleaner into the intake tube while holding the idle higher.

 

And spraying the MAF with carb cleaner probably finished it off. You should only clean that with MAF cleaner or electric parts cleaner.