I installed Velocity AP secondary cat deletes on my 14 V8 Vantage and immediately after doing so am getting a P0161 CEL, Service Emissions, which is Bank 2 Sensor 2 O2 sensor heating cirtcuit. The O2 sensors are upstream of the cats in my car and should not have been affected at all by the secondary cat deletes. I've cleared the code with my scanner, but it comes back every time on the second time I start the car up.

I'm pretty sure Bank 2 means passenger side downstream o2 sensor. I checked both O2 sensor's and everything looks ok although I don't have any way here to test voltage and much of the line to the ECU is not easily accessible on floor stands.

I'm allergic to dealer service fees which to diagnose and replace the sensor will be almost as much as my cat deletes plus a decent drive away, so wanted to see if anyone had any suggestions first? I'm presuming replacing the O2 sensor would fix the heating circuit issue? The part BG33-9G444-AB is about $85 shipped (used on ebay for $50 ask but figure better to do new for price difference.). There doesn't look like a lot of space to get to the o2 sensor, so is replacement an easy job on floor stands (hate getting under these low cars and have to put wheels under to be safe)?

I also purchased a tune from Velocity AP. I asked them if they could adjust the tune to have the car ignore the downstream o2 sensors entirely to fix this issue (which is what I'm 99% sure Switzer did with my 996tt with no cats to fix the CEL), but they suggested not to as it could cause issues with the car running too lean or rich and not adjusting appropriately. I thought the heating circuit would only matter on startup until the sensor is warm, but apparently it also maintains correct temp of the O2 sensor. They are the experts, so I'm tending to follow their advice.

Anyone have a DIY to change the O2 sensor, and also please confirm that this code for Bank 2 Sensor 2 is the downstream sensor (which presumably contains the heating circuit) on the PASSENGER side of the car?

TIA!

 

check connections and power at the pins for the heater circuit. If ok switch them from side to side and see if the code changes.

 

Hi Mike,

Here is the diagnostic page from the DB9 manual. Gives some things to check for to diagnose the sensor.



Also, here are the workshop manual pages on how to remove/replace.



I had to remove the cats when I changed out my clutch. It isn't too bad , but it's a bit of a pain that the wire are run behind the heat shield. I'm not sure if you can fish them through without taking the exhaust partially apart to release the shield.

No alternative to lifting the car - access underneath is good. You might be able to do it on ramps, but would be quite awkward I think, so would need jack stands.

Matt

Matt

 

I thought one O2 sensor was pre-cat and the other after? Otherwise, why have two sensors?

 

I am just going to order a replacement O2 sensor, tired of putting this off. Can someone confirm Bank 2 Sensor 2 O2 sensor is the passenger side downstream o2 sensor that needs to be replaced, part BG33-9G444-AB . I'll check voltages and connections while in there, but just going to buy something with free returns to use if I need it and not have to borrow lift time a second time.

TIA, really appreciate if anyone could confirm this.

 

Confirmed this is passenger side downstream sensor. Aston wants $386 for just the part (@@@!~!#!), so having them do it will be near $600! Scuderia parts has them, air shipped from the UK for $100, and I left it in the cart overnight and got an email from them to complete the transaction at wholesale which I just did for $89 for the part shipped air after tax. Will borrow my buddies lift and get this done during the oil change (10L motul 10w60 for $86 and a genuine filter on ebay for $33). These two things save about $1300 DIY vs dealership.

 

Well the Michigan and Las Vegas service managers both incorrectly told me bank 2 was passenger. That is wrong. Passenger side has cylinder furthest forward, making it bank one. I called the service manager back and was like wtf and be just say o ya, that’s right my bad. Fortunately we didn’t change the wrong o2 sensor first to realize the bad info. The correct info was given by Velocity AP, who did my tune and exhaust.

Anyway, replaced the o2 and car is back to running perfect without cel each time. Just wanted to correct the misinformation in this thread so someone doesn’t rely on it. In a 14 v8 vantage bank 2 is driver side!

 

It is scary that two service managers would tell you the wrong info. If they don't know something that simple what else are they telling people and charging them for unnecessary repairs.

 

I agree, when I called Vegas back (mi was not open on weekends) it was like he totally didn’t give a crap and fliped his answer back. Changing one of these sensors is a major pain and took over an hour with some funky tools to get them snapped in the wire brackets and heat shields moved.