I know that the P0038 code is because i removed the CAT recently since it was plugged which was causing a fuel dumping issue, but in my particular truck, will removing the CAT and not having the rear O2 sensor installed cause the truck to run rough and act almost as if i have a fuel issue? i have been battling a low power and high fuel consumption problem for awhile. i have fixed the over-fueling issue but i still have low power and a terrible idle (400-600rpm) and when reved up to 2000rpm or higher, like i said, it acts as if its not getting any fuel. When in park its reved up, rpms will durastically drop and almost die out..it does die when in gear. fuel psi is within spec though..any thoughts?? thanks!

 

Install a new stock cat and a new FACTORY O2 sensor and start from there. Make sure u have good factory plugs no after market junk.