Originally posted by Swazo:
As the title states, Dynomax bullet cats suck! Not even 1000 miles and mine is FUBAR.
I started to have issues with high amounts of load w/ low RPM/MAF counts that just got worse and worse. I let it sit over night and today after work, it was REALLY bad. After letting it idle a bit, I noticed that my whole exhaust system was GLOWING  Even my muffler's innards.
Once it cooled to a non-glowing state, I dropped my cat-back and my car was back to normal.... just louder. The POS is getting a gut job tomorrow!
A good test on how well the heat wrap and other forms of heat protection worked! No wiring, hosing melted or the like. Even my radiator (the DP runs along one side of it, and within 1/2-3/4"  ) was safe from what happend. My ECT didn't go over 210 the whole time.
I don't know what to tell you.. IN almost every case, glowing cats is a product of running too lean at cruise! Maybe at full throttle too. In the old days when air was added into the catalyst chamber to help complete combustion and reduce emisssions. Anyway, in too large of amounts the air would raise the temp of the catalyst and would overheat and crack it.
Too rich leaves them too cool and they clog up with soot.
So when you have glowing pipes and catalyst problems you'd better check your damned air fuel right away with a real O2 sensor like a wideband. Also, carefull you haven't already burned/damaged the O2 sensors. They may not read right after running so hot.
The factory programming has a calibrated heat range that if exceeded will cause the computer to add more fuel and richen the mixture so as to reduce combustion temps and cool down the sensors and or catalysts.
Something isn't right.
BTW
There is no reason NOT to run catalytic converters except environmental irresponsibility, or an all-out race motor that isn't driven except for track days!
Former owner of '99 CSVT - Silver #222/2760
356/334 wHP/TQ at 10psi on pump gas!
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'05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red
'06 Mazda5 Touring, 5spd,MTX, Black
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