1991 Acura NSX: Second Smog Failure Diagnosis

1991 Acura NSX Long Term Road Test

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1991 Acura NSX: Second Smog Failure Diagnosis

October 25, 2012


When our 1991 Acura NSX failed smog a second time, we bit the bullet and started shopping for replacement catalytic converters. All along we feared they were garbage, but we didn't want to spend the money if we didn't have to. Take a look at this one. The other is uglier...


First, a close up of the weld craftsmanship.


As promised, here is the other.


I think I put a cleaner bead of paste on my toothbrush this morning.


We shopped around for new parts. One shop quoted us $3,700 to replace everything from the cats back. This included using the exhaust tubing from a used NSX, new cats and our existing muffler. We really didn't need all of that hardware. Enter, the internet.

A quick scan of Amazon found a pair of Benchmark, 50-state legal cats for just over $400 each. These were the only we found. After tax and shipping they were in our hands for less than $1,000. A stop off at MD Automotive in Westminster was next.

Mark at MD installed the parts and cleaned up the creativity used by the previous welder. The new cats are bolt-ons. So clean-up required adding a section of pipe to replace the flexible pipe welded in previously. He then attached a new flange to bolt in one of the catst. The other bolted in fine with the existing hardware. Time for another smog test.

Cost for two catalytic converters and install: $1,195.97

Mike Schmidt, Vehicle Testing Manager @ 58,297 miles

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