I just replaced both upstream O2 sensors this morning (used Walker brand from AB) and now I'm getting a P0430 code. Is there a likely cause & effect for this code beyond bad cats? That's the only code that's popping up currently.

Also, the downstream O2 sensors are Bosch. Could it be a sensor problem?

EDIT: I added two photos of the corrugated tube behind the SAI. It broke around the time I bought the car so the previous owner just put a piece of tubing inside the corrugated tube and put clamps on each side. I might as well replace the old tubing with a new one, but could that be causing the P0430?

 

Why did you replace the o2 sensors ? If you were having problems most times it’s not the o2 sensors it’s something else causing them to read poorly



Could be so many reasons but I had same issue
the connector sometimes gets gummed up or wires not in properly
also if you have a bad fuel purge valve and sticks open you dump vapours and in my case it made engine run like crap and stinks like raw fuel or just rotten eggs and throws the bank 1 sensor 1 code

also a good smoke test to make sure you don’t have vacuum and exhaust leaks

 

I was consistently getting the p0130 code as well as the occasional misfire code for the past two months. I'd been getting the p0130 occasionally for the last year so I'm assuming that the O2 sensors were bad on at least one side.

I checked the O2 connections and they're connected as well as they can be. I don't get any odd smells other than coolant that is slowly leaking from the throttle body heater.

Is there a good DIY test for vacuum/exhaust leaks or do I need to get a kit?

 

Could regular octane gas cause a p0430? I realized that my wife put regular in the tank rather than supreme. I just ran through that tank and refilled with ‘93

 

You have to do some reading on here and check things out. Like I said it could be many things Start one by one inspecting wiring etc