Quote:
Originally Posted by 2.5Turbo
...Got it scanned at Autozoo recently and it showed a P0420 - exhaust catalyst efficiency below threshold. Damn, my cat went bad...time to spend another $900  |
Well, hold on, not so fast. I had an "exhaust catalyst efficiency below threshold" type of problem several times, but it was
never the cat... Bad spark plugs and 'leaky' spark plug wires produced this code twice. ANY regular misfire can overload the cat just enough to trigger this code. In my case, new plugs made it go away within 8-10 engine start-stop cycles. I came back, and a bad wire made it go away again...
Before you drop $900, be SURE it's the cat!
