P0420

[tb04]

My TB is now giving a P0420 code. Can someone help me out on this one? Im not sure where to start on this. Just had it to the dealership and had a fan clutch replaced and now I am getting this code. It has had 2 O2 sensors, MAP sensor, new plugs and boots, new fuel filter and fuel pump, throttle body cleaned and now this. It is still surging and losing power at times. At a loss as what to do next. Please help.:confused:

[800gofast]

The defenition for this code in my book is Catylyst System Efficiency Below Threshold(bank 1).

[RayVoy]

Have u had the cat removed? If not, it might be plugged or some what plugged.

[rubberman]

i thought code 420 was a gas cap loose or not on all the way

[jtblazeltw]

check this site out, if has some troubleshooting tips:

http://www.obd-codes.com/trouble_codes/generic/p0420-catalyst-efficiency-below-threshold-bank-1.php

[mturner333]

check this site out, if has some troubleshooting tips:

http://www.obd-codes.com/trouble_codes/generic/p0420-catalyst-efficiency-below-threshold-bank-1.php

Thanks a lot. I had been looking for this site and couldn't remember it right off the top of my head. Saved me a bunch of time and stress. :thx

[tb04]

Thanks to all for your suggestions. Will check in to the CAT and see what happens with that. I appreciate you all. This helps out alot.:thx

[exttb]

my cat died at 135,000 .mine plugged and couldnt get high rpm's... get a tune with the code removed...