Got the p0420 code last night...Cat is shot. Car still runs fine, but I get crap gas milage now. I have had terrible gas milage for a few weeks, maybe a months now, and did a few cheaper things first to try to fix it. here is exatcly what the print out from AutoZone say.
P0420
"The PCM has determined that the catalyst system efficiency for bank 1 is below threshold for the current engine operating contitions. (bank 1 identifies the location of the cylinder#1, WHILE BANK 2 IDENTIFIES THE CYLINDERS ON THE OPPOSITE BANK)"
P0420
Definition
Catalyst efficiency low-bank 1
Explination
The oxygen sensors monitro the catalytic converters ability to store oxygen.
Possible Causes
1. Catalytic converter defective (failure possible due to # 2, #3, or #4.)
2. engine misfire or running condition
3. large vaccum leak
4. engine oil leakage into exhaust-valve guide seals, piston rings.
The cheapest I have found that cat on line is 77.09. Anyone know of one any cheaper.
Ordered the magnaflow cat, and will order the res soon too....