Hello, I would greatly appreciated any input on these codes I pulled this morning...
Is it possible bad O2 sensors could trip all these? I'm hoping I don't need new cats but below is a real mess. A week ago, I had only these codes:
P1606
P0421
P0431
P1131
P1113

Then, I decided to test the resistance on all four O2 harnesses (all were around 10ohms, according to the DIY I read, below 20 meant the O2's were ok). The O2 contacts were corroded at the wiring harness so I sprayed them w/ electrical contact cleaner. Now, I'm checking to make sure I fully plugged the O2's back in at the harness. I did get a suggested repair letter about reflashing the ECU to fix an air/fuel threshold tolerance.

Now, I have these codes and the engine is running rough, hesitant to start (takes 2 cranks), and puts out white and black smoke intermittently, and exhaust smells of gas and other horrible smells...

A4/B5/2.8, 172K

P1606 Rough Road Spec Engine Torque ABS-ECU Electrical Malfunction
P0421 warm up catalyst efficiency for bank 2 is below threshold
P0431 warm up catalyst efficiency for bank 1 is below threshold
P1131 Bank2-Sensor1 Internal Resistance too High
P1113 Bank1-Sensor1 Internal Resistance too High
P1523 Crash Signal from Airbag Control Unit range/performance
P1128 Long Term Fuel Trim mult.,Bank1 System too Lean
P1130 Long Term Fuel Trim mult.,Bank2 System too Lean
P0130 O2 Sensor Circuit - Malfunction (Bank 1 Sensor 1)
P0300 random/multiple misfire
P1602 Power Supply (B+) Terminal 30 Low Voltage
P0154 O2 sensor related?
P1423 Sec.Air Inj.Sys.,Bank1 Flow too Low
P1128 Long Term Fuel Trim mult.,Bank1 System too Lean
P1130 Long Term Fuel Trim mult.,Bank2 System too Lean
P1136 O2 sensor Bank 1 Too Lean
P1138 Long Term Fuel Trim Add.Fuel,Bank2 System too Lean

 

Sounds like you might need new O2 sensors, fuel filter(or pump) because it's not getting fuel(for the too lean codes), check your alternator/battery, check spark plugs and, for that matter, fuel injectors, and check your cats. I'm not sure what internal resistance means but checking for clogging in the exhaust sounds like a logical place to start. If it's pre-'99.5 you can try unplugging the MAF and see if that helps anything at all too. For the ECU get a multimeter and check the relays. They're located in the ECU box which is located at the upper driver side corner in the plain, black plastic box. P1423 makes me think your secondary air pump is shot or almost shot.

 

I think definitely your primary O2s are shot. SAP low airflow could be the pump, a broken pump line, or a bad secondary O2 sensor (that's how the ECU reads SAP flow). Given that you have other codes indicating secondary O2 failures, I'd look at those too. First thing is clear them all and see what comes back. Deal with those that do. If they all came back and it was my car I'd change the primaries, clear codes, and see what goes away, and then reassess based on the codes that remain.