same p0430

[crankor]

I'm out of ideas here. I've had the same reoccurring 430 code since I've gotten this car. I've replaced both cats since one def had a hole in it, Y pipe and both bank 2 sensors. After putting on the new cats, code was gone for several months. Around winter it came back. I thought maybe an exhaust leak again but that doesn't seem to be the case. Before replacing the b2s2 sensor, I cleaned the old one and it was good for about 5 days before triggering the code again hence why I assumed it was indeed the sensor. After putting the new one in it triggered the code next day. It doesn't makes sense that it would be the converters since it should show codes for both sides right? Maybe the magnetic clutch is malfunctioning causing some weird exhaust mix?

I'm about to just use that spacer!

[VStar650CL]

I presume the new cats are aftermarket? It's not uncommon for aftermarket Fed cats to be less efficient than the originals. I'd try a new A/F sensor (front O2) first, but if it still codes with both sensors new, a spacer may be your only good out.

[VStar650CL]

PS - Did the new cats come with proper heat shields? That can cause problems too. We see it more often in winter on FWD platforms, but the shields aren't just there to protect the car from the cats. They also help the cats reach operating temperature when there's highway air gushing past them. The newest stuff largely has exhaust temp sensors to let the ECM judge the cat temperature directly, but older NA engines don't have that. The ECM needs to estimate when the cat is ready for testing from the engine temp, so anything which makes the cat slower to warm up than the engine can cause the ECM to underestimate its oxygen storage.

[crankor]

These are the ones I got. https://www.ebay.com/itm/303915211189

The part thats bugging me is its only one side and went away for 5 days but now comes back same day with the new sensor. My brain is scrambled ha. Guess ill order the spacer. Both upstream and downstream have been replaced on that bank

[VStar650CL]

With China-cheap converters, you probably just got a weak one. The factory ones also had full shields, so that may be contributing as well.

Exactly when a cat code pops back up after erasure depends a lot on driving conditions. The ECM pretty much only tests them when you're at a warm cruise, and generally they're 2-trip codes, meaning the cat has to fail SRT twice before it lights the MIL. So "days between" doesn't necessarily tell you anything unless your drives and driving habits are extremely predictable.

[crankor]

Hmm. Still kinda weird to me its only that one side before and after replacing the cats. The 5 day run was alot of highway driving but ah well. The new sensor is reading pretty sporadically too. Im tempted to put in the old one just for kicks but I think its already long gone. Im just gonna get the spacer anyways but the issue still bugs me

[VStar650CL]

Those voltages are peaking around the right voltage (0.8V) but going way low on the downswing. They should be bottoming around 0.3V, which means your sensor is a little funky. The ECM isn't flagging it because dead O2's almost always exhibit high voltage, not low. The ECM is seeing 0.8V with oscillations, so it's calling the sensor okay. The oscillations around 0:30~0:35 are what you should be seeing at a steady cruise, but without having a corresponding graph of throttle position I can't say much about that.