I recently got the p0420 code and narrowed the issue down to needing a new cat. Thought i'd be smart and went to Walker identify the exhaust for a basic '04 Nissan Xterra XE, 4WD, 3.3L. Found the parts for the manifold cat, boom, purchased from Amazon. Thought I was on the road to repairing this, part comes in, take it out to the garage to drop off the cat and low and behold they don't match!

I purchased this puppy: Walker 16500. But when I went to match it up. It looks like the manifold cat and the manifold are a single unit. They certainly don't have the triangular flange as indicated. See picture: enter image description here

I then decided to search for the exhaust manifold, assuming that the vehiclle/model had a singular exhaust manifold/cat and only found an exhaust manifold that appears to match the cat manifold that I purchased (and was incompatible with the installed exhaust manifold). What have I missed?

  • Are you sure what you purchased won't fit your application? You may need to purchase the exhaust manifold and change out the whole thing. Apr 22, 2016 at 15:30
  • 1
    That style manifold converter combo is used on the xterra vg33e engine the convertor you bought is intended for the xterra vg33er engine. Take a look at amazon.com/AP-Exhaust-641243-Catalytic-Converter/dp/… I couldn't find a OE Part number.
    – Ben
    Apr 22, 2016 at 21:22


You must log in to answer this question.

Browse other questions tagged .