Catalytic Converter Breakin?

Last week for the first time I had my 96 Tacoma 2.4l fail smog on high HC measured 117 at 15mph and 60 at 25mph, with 170k miles and talking to an old neighbor, (retired master tech for ford) he reccomended replacing the Cat. I had the cat replaced and only drove for about 25 miles before retesting and it failed, HC went up from last test, CO and NO went down.
I had the old neighbor look at it and he verified with the fluctuation of the back O2 sensor from .2 to .8, and the outlet of the cat being 20* lower than the inlet that the new Cat was bad.
I called the muffler shop and he said that it needs to be broken in for at least 100 miles for it to work correctly. I and the neighbor have never heard of this. When I checked it today with my cheapo temp gun the outlet is showing 60 warmer than inlet, my Flir IR camera was maxed out at 300+ and couldn't show a difference. I have put about 100 miles on since the new cat installed.

Is there really a break in period for them, seems like a load of crap to me being its a chemical reaction that makes the magic happen?

 

Maybe I missed it but what kind of cat did you get? Cheap aftermarket cats have way less material in them that filters emissions. If you live in CA you have to get CARB certified ones, any CARB certified cat should pass. Some are better than others though.

I've never heard of a break in period for them

 

Load of crap!

 

Also are you throwing a code for the cat? P0420 would be it

 

no codes were read both days

 

Guy will probably tell you your blinker fluid is low, too.

As others said, that sounds like bs.

 

How did you come to find that you need a new cat in the first place? Did it throw a code at the smog center and that’s why it failed?

 

I’m am also having trouble passing smog due to the catalyst not being ready. I have no pending codes and have driven the car hundreds of miles. I have also followed the Toyota drive cycles with no success. I have replaced both O2 sensors, throttle position sensor, radiator, thermostat. I’m at the point where I think the catalytic converters may be bad.

 

I wonder if the Muffler Shop meant it takes time for the test to cycle?? I have been told that before and corrected them on the spot. Most people might be confused trying to understand the OBDII system .

Just a thought,

 

Check them; an IR thermometer is a good indicator. Look for temperatures in the 4-600 degree range. If it's crazy hot, or cool enough to touch, is probably fuckered.

 

Possible; some cars can take a while to complete a drive cycle if you don't meet all the conditions, but that's a pretty slimey way of explaining it.

 

i recently had my cat and sensors cut off & boosted, replaced with new sensors & the magnaflow 50state compliant cat and it took almost a week of regular driving for the check engine light to flick off

 

That's because it takes a certain amount of driving to reset the emissions monitors, once they reset they see the proper reading from the o2 sensor behind the new cats and the code goes away.

Sorry to hear about your cat converter getting jacked, it's becoming a big problem everywhere lately it seems. I have the 50 state Magnaflows as well for 4 years now, been running great.

 

Update, retested at a different place with about 120 miles on new cat and 80 miles after second test that epicly failed, this place passed with flying colors. It was also $50 cheaper. Not sure if the first place was doing some shady stuff or what but I'm sticking with the other place across town from here on.

 

What was the reason why it failed?

 

HC way too high almost double allowed at both speeds

 

more than likely the issue with the first shop was their equipment. Your 96 is a "tail pipe" test and if the shop does not maintain the filters on these you will get false readings. The vacuum pump that pulls the gasses into the analyzer also pulls in water from the exhaust pipe, dampens the filters and drags dirt and debris into the line set.