Failed CAT help please.

[jadessi]

i have an 06 pathfinder with 77k miles and service engine light came on. my local mechanic said take to dealer as we need a new catalytic converter and oxygen sensors. apparently catalytic converter covered until 80k miles. i'm wondering if anyone can tell me if they will replace the second catalytic converter as part of the warranty and more importantly if this is potentially related to the transmission/radiator problem. i'm guessing that at 80k miles i should do the bypass.

[NmexMAX]

They should.

Just recently had one mine replaced at no charge with ~75k on the clock.


As for the O2 sensors, that's not covered under the emissions (8yr/80k) warranty, but if they're nice enough, they might do it.

[jadessi]

have you done the bypass?

[NmexMAX]

have you done the bypass?

Have not done that yet.

Also, haven't seen if it's been clear if the 08+ V8 suffers from this problem.

I was wrestling with an O2 sensor last night, and need to put thing back together after I get home from work, I should look into doing it then.

[jadessi]

what do you think a local mechanic would charge me to do the O2 sensors?

[smj999smj]

Seems to me that they are trying to cover their ass. If you have a three way catalyst code (P0420/P0430), you likely do have a bad cat, but probably don't have bad oxygen sensors. If you have oxygen sensor code(s) along with catalyst codes, the catalytic converter may be fine and you just have a bad oxygen sensor(s). Replace the sensors and erase the codes and see if the code comes back in this case. In the case of three way catalyst codes, they only refer to the front catalyst as the front catalyst is the one monitored by rear O2 sensor. The post catalytic converters seldom fail as the primary cat tends to be a sort of filter of the exhaust before it ever gets to the rear cat.

[jadessi]

thanks!

[NmexMAX]

Also, bad O2 sensors can cause bad cats also, (lean/rich condition can both damage them).

Not sure what they would do at that point, blame the O2 sensor and not perform the warranty work, or be kind enough and meet you half way (more like 70% of the way) and replace the cat(s) and have you pay for the O2 sensors.

Or, best case, they replace everything.

Let us know how it turns out.

Recently I had my manifold/cat assembly replaced under warranty (08 MY/73k miles), and shortly thereafter an O2 code (A/F sensor code) popped up.

They are very sensitive and could very well have been damaged during the install of the manifold/cat, and that was the dealers little way of saying, yeah, we replaced the manifold under warranty, but look, you now have an O2 sensor code.

The O2 sensors are easily accessible from the fender area. Removing the tire and splash shroud and bam, it's looking right at you.