[elt0m]

I had some issues with my car last year, even with a rebuilt WUR and fuel head. The issue was way far from my fuel system—a major air leak. Look at all your intake runners to make sure they are all bolted down and secure. Mine were loose, and when the car was at high rpm, the AFR was oscillating and backfiring when decelerating. Also, look at your bonnet on the top of your throttle body. At high rpm, the car will suck air from anywhere so your AFR will become lean.