[superchiem]

Yup a "Catalyst System Efficiency Below Threshold" P0420. I'm on 32,000 miles on my truck and out of the blue i get this code.I have a test pipe, but I haven't thrown a code for 20,000 miles. Well first off i check if there were any exhaust leaks, but seems fine. So my next assumption would to test the o2 sensor. How would i test that? Oh yeah I rested the light, but it came back after a week. Any other ideas would be great!

thanks,

navy

 

[XRobber]

lol
before you spend all sorts of time checking your O2 sensor...
Check your cat. I have done a lot of research on this code, and P0430 (Catalyst System Efficiency Below Threshold Bank2).

 

[redrunner]

You've got a test pipe, your check engine light is doing its job. This is why URD and other companies sell "o2 simulators" (for people who run test pipes)

 

[Firdaddy]

You've got a test pipe, your check engine light is doing its job. This is why URD and other companies sell "o2 simulators" (for people who run test pipes)

for real.. i dunno why it took so long.. do you have the first cat still? mabey it finally died.. either way time for a cat or o2 sim :waytogo:

 

[97Taco2426]

I had that code repeatedly come on, and I just shut it off every time. And now it hasnt been on in almost a year.

In my case, I was going to replace the O2 sensors but never had too in the end.

 

[3.4v6]

so my taco threw this code at me today. P0420. and i still have my cats. any ideas?

 

[BatuKing]

If your throwing a P0420 code with a test pipe then the ECU is doing its job.

Now if you have a CAT installed and have that code,, you will need a new cat converter, now for the 3.4L guys just get the first cat converter, those with the 4 cyl, you gotta get both .

 

[gixxertaco]

check out my thread i got the same code and this is what the dealership is doing about it it was code p0430 "WARRENTY WORK AT 29103 MILES

SORRY I DONT KNOW HOW TO MAKE QUICK LINKS

 

[BatuKing]

check out my thread i got the same code and this is what the dealership is doing about it it was code p0430 "WARRENTY WORK AT 29103 MILES

SORRY I DONT KNOW HOW TO MAKE QUICK LINKS

yea but he has a test pipe so no warranty there