2004 RX330 AWD w/ 180K miles

Symptom - CEL light with VSC light code P0430 (Bank 2 cat reading error)

Since I bought my car a couple years I've been plagued with a frequent P0430. It is more frequent on cold days than hot summer days. I keep a code reader/eraser in my car and am quite quick are erasing it when it pops up. I tried replacing exhaust gaskets it didn't help. Over the last year it has been getting a little more frequent and being a cold winter it comes on maybe every 100 miles so time to try stuff.

Last week I decided to try giving the Dorman 42009 "spark plug non-fouler" trick a try since I'm a cheap bastard won't spend $500-3000 on a new cat... so far so good. The idea is the non-foulers space the O2 sensor out of the direct exhaust so the readings are more stabilized hopefuly no longer throwing the codes

Tools needed:
drill w/ 1/2" bit
Dorman 42009 non foulers
22mm open end wrench, cresent wrench or specific 22mm O2 sensor socket

Make sure engine is NOT hot

1. Get Dorman 42009 - got mine at O'Reillys but you can get them almost anywhere for $11
2. Drill one of the foulers out to 1/2" - I use slow speed and a decent amount of cutting oil. Clean out the threads when done
3. Screw the drilled out fouler on top of the other fouler with the provided washer inbetween. Drilling it out allows for the O2 sensor to screw in
4. Jack up front of car
5. Bank 2 is at the front of the car, as soon as you look underneath you'll see the O2 sensor... remove it w/ 22 mm open no need to disconnet the electrical connector
6. Thread both non-foulers into exhaust just behind front most cat (as seen in pic) that is the front bank cat
7. Twist O2 sensor 7-8 times backwards then thread it into the non-foulers twist so when it is fully seated the cord should be almost straight/unwound.

You're done. Total time after drilling out fouler is maybe 10-15 mins VERY easy all of one item to remove/reinstall



Dorman 42009 non fouler

Drilled it out to 1/2" then clean all burs out

View from under front of car, you can access it without removing any under shields. Maybe count how many twists to remove the sensor then when reinstalling it twist the same number of turns so you end up with a straight wire. Sensor takes a 22mm open end wrench

Finished product.. O2 sensor spaced out from direct exhaust

 

Nice work @Leeper .
Do you have live data on your scanner?

Just wondering how the fuel trims for that bank look after this mod.

I have a persistent 0430 code too and I clear it about once a month.

My car is on the rag... haha

 

I do have a scanner and techstream I'll see what I can come up with. I'm hopeful this works I'll know over the next week or so that's how long it took to get the CEL to pop up.

 

I did this awhile ago. It started popping again after a few years. I just clear it every month or so.

I too am cheap.
However, since last time, I'm at almost a thousand miles and it hasn't popped yet.

 

So far so good, I' ve got a few hundred miles with no CEL code whereas before it was coming on very frequently.