Hi everyone.


I have an 05 DB9 with only 5800 miles on it. I've only had the car a few months, but drove it yesterday and noticed it wasn't idling very smooth. Yesterday I also couldn't avoid a big plastic bag that got caught under my car and melted a bit on the exhaust behind the rear passenger wheel. I removed most of the bag but there is still some melted plastic on the exhaust pipe. That part may or may not be relevant.


Today, my car hesitated a little and then threw an emissions code. The OBDII scanner at the local auto shop says its'a a Bank 1 Sensor 1 and Bank 2 Sensor 1 fault.


First off, do you think that bag had anything to do with this? It seems to only be melted on the outside of the exhaust pipe and I expect it would eventually just burn off. Second, if I need to replace the O2 sensors, is this a job I can tackle myself and where are the cats on this vehicle? I'm also not sure where each of these sensors are. Any guidance you can lend me would be great!

UPDATE: For any forum searchers, I am tentatively reporting that we found the issue, as the car seems to run fine now without misfires. Cause was a cracked evap line in the fuel tank, sending unmetered liquid fuel into the fuel tank. This flooded the carbon filter above the fuel tank as well, which needed to be replaced as well. Replaced both parts (among others in the fuel tank) and all appears to be well again.

 

I doubt the bag had anything to do with it.

I had the same OBD error come up on my V8 Vantage. The fault code further specified a delayed response from sensor 2. I talked with the dealer and they said that AM has buggy OBD software and often these errors clear themselves. Sure enough, the next morning the messages were gone. My car didn't run roughly as yours does, so this may not be your circumstance, but I'd encouraged you to start and stop the car several times and see if the errors clear.

 

Can you post the actual code(s) that was triggered? Also, we need to figure out what side of the engine the code(s) were triggered. It's either PCM1 or PCM2, right or left side of the engine, respectively. If in fact the O2 sensors need to be replaced, that's a pretty easy job with basic mechanical skills...but let's not jump there yet. I *highly* doubt the plastic bag had anything to do with it. Emissions codes are triggered over time, not on a single event...

-Dan

 

I don't believe the bag had anything to do with the issue. I do recommend you drive the car and also give it some spirited runs. I've noticed that if I change my driving habits a bit, my V8V can flag emissions codes but clears after further driving.

Don't panic yet

 

Hey guys and thank you for your help. Codes were P2196 and P2198.

In other vehicles, normally pulling a fuse to reset the computer and allowed codes to clear to see if they return will fix things. Is this not a normal practice in our cars? What I took from your comments is that codes clear themselves rather than requiring a reset.

 

Sorry for the glare. It reads:

O2 Sensor Signal Biased/Stuck Rich/Bank 1 Sensor 1

O2 Sensor Signal Biased/Stuck Rich/Bank 2 Sensor 1

 

Got it. Appears to be a pair of bad O2 sensors. If it's the original O2 sensors, they're probably ready to be replaced anyway; I've read they have a useful and "accurate" 10 year life span on daily driven cars.

The screenshot doesn't say which side of the engine but probably worth replacing all 4 pre-cat O2 sensors anyway (2 pre-cat sensors on each side of the engine). You can do so WAY cheaper by buying the equivalent Ford part. I recently picked up 4 brand new Denso O2 sensors (part#2344045) for $111 TOTAL shipped from RockAuto (referenced from 2000 Ford Crown Victoria 4.6L V8 but used in ALL kinds of Ford cars and trucks). In comparison, the exact same Aston part is: 1R12-39-10174 at $160 each. I replaced all 4 of my primary O2 sensors with the Denso part# above and they work perfectly. If you choose to go deep on diagnosis before buying new O2 sensors, here are the pages out of the service manual. Hope this helps!

 

This is great, thank you! Couple more quick questions:

1. Is this from the workshop manual or is there an actual service manual as well out there that we should own?

2. Are you saying that Denso part # will work with my 2005 DB9 and for the precats only? Is there anywhere I can check this online (how you found out that they're the same) so I can have a good point of reference?

3. As I understand the pre and post cat connectors are different. I will just replace all 4 pre cats with the part you recommend if it's an above-hood job, but where can I find info on the post-cat sensor equivalents, for future reference?

Thanks for all of your help. I used to drive MKIV supras btw.

 

1. One of the members here provide me a link for the DB9 workshop manual. See my post here for the link (https://www.6speedonline.com/forums/...0174-code.html)

2. You can lookup Aston Martin OEM part numbers for your 2004-2012 DB9 here: https://www.scuderiacarparts.com/par.../151/668/23917 . As indicated, the Aston part number for your primary O2 sensor(s) is: 1R12-39-10174 -- exact same part number as I listed above. To cross reference for alternative (but exact same part), I simply Googled this part number and look for a page like this one that provides all alternative part numbers: https://partinfo.org/ford-5w6a9g444b1a/ . Also, when you remove the original O2 sensor, you will find the generic Ford part number stamped on the side of the sensor. I took this pic of one of the ones I just replaced; can only see part of the number since it wraps around the sensor but the full part number reads: XC2F-9F472-B1A. You could also Google this part number and get a TON of hits (this is how I found the part on RockAuto.com).



3. The post-cat sensor equivalents are on the same Scuderiaparts link in #2 above. The post-cat sensor part numbers are: 1R12-39-10175. Following my own advice, I Googled this part (but didn't get a solid hit so I removed the dashes in my search) and found all the alternative all cross reference part numbers here: https://partinfo.org/ford-5f9a9g444b2a/ . Take your pick of all the part number choices to source the part via Google. :-)

Hope this helps!

Yeah, I've owned an '88 MKIII turbo and '97 MKIV turbo. And about 10 years ago, I restored an '85 MKII and swapped a 2JZ with single turbo into it. Last winter I dropped in a T56 Magnum 6-speed transmission. Still own it and goes like a missile. ;-)

-Dan

 

Awesome, and thank you for taking the time to explain all of this to me so I can self-help myself in the future! When i replace these, will the computer drop the code on its own or do I need to do a battery disconnect?

 

Hey know this was a while ago but did changing the O2s fix this for you? In the exact same spot with my DB9

 

Hi Travis, follow the continuing saga here:

https://www.6speedonline.com/forums/...-you-help.html

The short of it is I replaced all four upstream O2 sensors with OE equivalent sensors and replaced my battery, but my problems are the same and maybe even a little worse now. The car is going into the shop for diagnostics and I will post a follow-up when we have something definitive.

 

Ah what a shame. Was hoping to get this resolved this week but doesn’t look like it’s happening now 😞 I can say that I ordered all 4 O2 sensors and they should arrive tomorrow but now I fully suspect that they won’t help. I can also tell you I originally replaced all 12 coil packs and spark plugs following Steve’s guide at Aston1936 as I had the same rough idle issue as you and him but this also didn’t fix the issue. Looks like you and I are stuck in the same boat and this is a more serious issue that can’t be fixed by throwing parts at it. Did you take it to a independent mechanic or Aston Martin themselves? Looking at this $1200 bill from AM from my cars history papers for essentially a damn battery job, I assume they will charge a arm and a leg to just breathe on it but I also feel kind of at their mercy. I do feel strangely a little easier knowing I'm not the only one with this issue

 

It does appear that you and I are in the same boat, as coil packs were my next guess, but my car isn't showing a lot of misfires so I don't think that's the issue. Since I'm not very local to an AM shop it has taken me a while to schedule it but I can let you know what they determine so that maybe it can help you take a closer guess as to your issue, if you have some time to wait.

You can also check your local AM's diagnostic fee, which isn't always exorbitant as with other AM dealers. If it isn't too much, throw your car in there and let them hook their computer up to it and give you an answer for hopefully only a couple hundred bucks. Sure beats guessing.

 

I think I’m going to have to send it to them today. This is actually a rental car I own and I stand to lose thousands by not getting it running this week. Losing hundreds to AM sounds better than losing thousands. I’ll keep you posted if I find anything and let me know if you have better luck!