Reply To: Failed emissions test – think my cat is clogged but not sure

[miawalker]

A quality aftermarket catalytic converter that meets local emissions standards will perform just as well as OEM for a 2009 Altima in everyday driving conditions and the price difference is significant enough that most owners who research this properly choose the aftermarket route without any regret. The key is making sure whatever is fitted has the correct specifications for your engine and meets Abu Dhabi inspection requirements rather than just being the cheapest available option which is a question worth asking specifically before agreeing to any particular part. Backpressure testing is actually one of the more reliable ways to confirm a clogged cat before committing to replacement because it gives you a concrete measurement rather than a diagnosis based purely on symptoms that could theoretically have other causes. Power restoration and fuel economy improvement after a proper cat replacement on an Altima at this age are almost always immediate and noticeable because the engine can finally breathe properly after years of increasing restriction.