p0420

[suzook]

So I got the "wonderful p0420 a couple of days ago, and doing a search suggests a catallytic converter....Any other areas i should look into???

[Towncivilian]

How many miles are on your Pathfinder / QX4? Does it consume oil?

[suzook]

How many miles are on your Pathfinder / QX4? Does it consume oil?

130k miles....only driven it about 300 miles...oil level looks same as when i purchased it. Runs great...im not about to replace the converter. I might try the o2 sensor spacer...its just a winter beater, so im not about to throw alot of $ into it. BTW does it have 2 downstream sensors? Left and right? Why does just the one side give a code?

[Towncivilian]

Yes, there are two downstream sensors. P0420 is for the passenger's side catalytic converter. I forgot to ask, what year Pathfinder do you have?

You will also want to check for air intake leaks (ensure air filter is sealing well and that there are no cracks or holes in the intake tubing by spraying starting fluid or brake cleaner around the intake with the engine idling and listening for an RPM increase - if RPMs rise, you've found a leak) and exhaust leaks.

It may be worth a try to use two 20oz bottles of Chevron Techron Fuel System Cleaner in back-to-back tanks to see if that would help clear the code, too. Change the fuel filter afterwards too, it probably hasn't been done in eons if at all.

[suzook]

Its a 2002...bought it from original owner, with most of the maint records. I will check the intake, and give the Techron a shot. I have a few mos left on nys inspection, so im not in too much of a rush. And yea, that fuel filter looks original!

[suzook]

So I purchased a Bluetooth obd2 adapter, and am using torqueapp on my phone. Reset code, drove about25 miles...no code yet, the app offers real-time monitoring, and the o2 sensors seem to be within spec for now. I guess I will find out soon if it was a glitch...or else I'll try the ole spacer trick on the o2 sensors.