finally found cause of rear cat plugging up !

[montana tom]

2007 OBW auto trans. This car was giving me fits trying to find out what was causing it to lose power badly,to the point of leaving you on the side of the road. In an earlier post I tracked down a clogged second cat as the culprit. Replaced cat and its fixed ... right?... wrong ! As was suggested by several respondents , something caused that cat to fail !  Car seemed to run great for a while until it misfires, only code it throws is misfire. It does stay running now,... just poorly.  I have it in the shop ... its running but missing ,clear the code and it comes right back. I finally shut the engine off and open the hood,you know to swear at it ... what do I see ... the brand new second cat is glowing orange !!!!! Seems that when it's misfiring it's dumping raw fuel ,down the exhaust !!!  After it cools off and the shop doesn't burn down, I do a little research and I discover that it's the coil heating up and misfiring. One 75.00 coil and both O-2 sensors later and it really is fixed this time ! At least we didn't melt down the new cat , or the car, or the shop...  Talk about a hair puller !!! Code reader was telling me what was very obvious it's misfiring !! ahh yea we noticed !! Only after seeing the symptom of the red hot cat was I able to track the misfire back to the coil.

[gbhrps]

montana torn,

 

Glad you found the problem! Thanks for sharing the solution!

[lstevens76]

And thus is why always look beyond the initial problem. :-)

 

And good job on finding it before it caused a lot more issues. :-)