^^ forgot to mention I already did that, and reset the codes. Issues was back within 4 days. Again, rich bank1 and bank4.

Joe do you think I might need a new MAF sensor? What are possible ways of testing it? Thanks for all the help.

 

You might need that.. or maybe a New O2 sesnor might be needed too....

Dealership should be able to confirm.

For Bicohon (and anyone else),


The Rear OEM O2 Sensor part number is: 89465-30730
Covers both Left & Right sides attached to mid-pipe

You can buy them from Desno directly

~ Joe Z

 

Thanks Joe, unfortunately at the dealership the moment they see an aftermarket intake they always want to blame it on that and do no further research.. I might put my stock back on and have them check it that way.

 

LoL... Just tell them it's the same intake that the F-Sport is based off of...

Or slap the OEM one on for them and make them happy..

It's not uncommon for the O2 sensor to fail as seen with Bichon's issue.

You just have to know which one failed.... Sometimes those front exhaust gaskets fail too..

~ Joe Z

 

For those following my saga, I figured I'd post a follow-up. Two days after my check engine light came on with the P0420 (and before replacing the sensor or phoning my dealership), it went off by itself. I figured it would be back, but after six days of driving that included long trips, short trips and my usual commute, it is still off.

One of my acquaintances mentioned that he often gets CEL for a few days around this time of year when the stations change to winter blend gas. (he didn't check his car, not a Lexus, to see what code was set) An interesting thought, though I am skeptical that it is related to my problem.

At the moment, I'm tempted to do nothing but wait to see if the problem returns.