OEM and Aftermarket Catalytic Converter emissions

The test equipment is a COSA 707. It's a 7 gas emissions analyzer for industrial combustion processes . It's not exactly optimized for automobile emissions, but it's also not a cheap device and should at least allow us to compare OEM catalytic converters to some aftermarket cheapos. It's set on diesel, because it's the closest option. Doubt it makes any difference.

I'm not going all crazy with trying to analyze a million different scenarios. This test was performed on a recently purchased 275k mile 2008 Gen 2 with a converter assembly that was replaced a couple years ago due to a P0420 code. I got home from work this morning (driving my 2007), fired up the 2008 and cranked the heat to max, in manual, with all the windows down so the car would run continuously. I also fired up our 2004 Santa Fe 3.5L (ICE, no hybrid) Went into the house, fed the pets and made breakfast. Then went back outside to the 2008, still running and now warmed up. Insert the sample line into the exhaust pipe and here you go...was interesting to see the CO measurement was moving around a bit.

 

Then I walked about 100' to the Santa Fe (3.5L ICE) and after allowing the COSA to breathe clear air for a while, stuck the sample tube into the Santa Fe exhaust.....rock steady. The NO readings were moving between 2 and 6 ppm.

 

Went back to the 2008 Prius because I realized I didn't check NO and did a bunch of quick photos to show the CO cycle. Interesting that the CO drops until the O2 reaches 0, then the CO comes back up fast. Imagine that, no O2 to combine with. But, the NO readings stayed on zero. Must be something in the ratio control circuit cycling. Here's a bunch of photos.

 

And then I went over to my 2007 daily driver (which had been running for over 10 minutes, set up just like to 2008) with the $114 dollar catalytic converter from ebay...................the first and last couple photos were with the sample line in fresh air



Yeah....I don't think I'm going to lose any sleep over the aftermarket converters.....

 

And then....I went back to the Santa Fe for another round. Here's a bunch of photos. You can tell if it's sampling or not based on the gas temp. Some photos show after I take the tube out, just checking that things go back to standard atmosphere readings.



.

 

We have to keep in mind these measurements were taken only at idle. For all we know, 70 mph on the highway may be enough flow volume to overwhelm the cat. I'm far from an exhaust expert but I like that even the aftermarket cat had 0 on the NOx, while our completely stock, and decently maintained, Santa Fe didn't. So, on initial impression, it seems to at least be as good or better than an early 2000s ICE setup.

Also, none of the aftermarket cats I've installed have thrown any codes yet. I've had my 2007 at maximum throttle position many times (aahem...electrically limited), so if that didn't overwhelm the cat, a mere 70 mph certainly wouldn't.

 

It's been decades since I've lived in a state that does annual inspections, but I seem to remember having an idle sniff performed and then one of the techs pulling my car onto a set of rollers a few times.

It wouldn't surprise me if the roller tests have fallen by the wayside considering all the self monitoring newer cars perform.

 

conveniently enough, irt emissions testing, NJ is the exact state I was referring to. Toms River HS North, Class of '85...…and never stayed in the state for more than 2 weeks a year after graduation……...

I agree with you on the 2008.

I merely did this to throw some quick data out there for everyone questioning the viability of aftermarket catalytic converters. I don't have the time or proper equipment to do full boogie testing. It would be great if anyone that has better (or proper) equipment and spare time could do additional testing and add the data to the discussion.

The 2008 needs some work. The car is cosmetically very, very good and was taken to Sparks Toyota every ~5k miles. I just printed out the full maintenance history yesterday. 55 service records and the car has exactly 275k miles when I bought it. In Jan of 2017, the car was taken to the dealer and diagnosed with a P0420. Prices were quoted, etc, but appears work may have been declined. Write up was not as clear as I would have hoped, but there's no mention in any follow-on service records of the code returning (~40k miles added to odo since code was cleared). I will likely do an identical check on this car again after installing the aftermarket cat to see if it causes any changes.

The final service report 8/20 states a C1345 is present, would not clear after a relearn was performed, needs abs actuator replaced, needs front brakes, rear brakes and water pump replaced. When I techstreamed it, I showed a C1345 and C1368/505. Historically, a bad combination, but I haven't had time to really get into it yet. There's no doubt about the water pump, it sounds horrible. I can't believe it survived the drive from Myrtle Beach to Columbia. First thing I did on the ay out of MB was stop and get a gallon of coolant and 3 gallons of water just in case. A few things I want to try before replacing the abs actuator, but that replacement is fairly likely to happen. I figure I'll verify the brakes, refresh anything that needs it, to a good bleed/flush and try the relearn again. If it's a no go, then actuator.

 

I bought them from ebay. Some were from user "Detroitcat" and some from user "funsport-usa".