Hi Calcifer33, I have replied to another one of your threads so apologies for the duplication.
Have been following your issue with great interest as I have a similar problem but different. 08 DB9 update model. Driving along, car suddenly goes into limp mode with "check fuel system" previous owner had both fuel pumps replaced to try to rectify which obviously it didn't. This happened to me twice at about 2 month intervals (its not a daily driver) both times I pulled over, turned the car off and re started and all good. It has never had lumpy idle and runs like a dream (except in limp mode of course). 2 weeks ago it did same again except it added check emission system, tried to pull over, stop and restart, no good, stayed in limp mode, fortunately I was only 5 minutes from home, also this time after I got home there was a stink of cat converter. Spoke to my mechanic (AM trained and 10 years on AM) said to try car next day and report back. Started car, and apart from the check emission message, no issue. The reason I am interested in your story is that my mechanic mentioned the crack in the fuel tank pipe thing when I told him it does not seem to happen when the fuel tank is less than half full. He doesn't have an AM code reader but his Snap On code reader came up with : 2106 throttle actuator and 2195/2197 O2 sensor signal bias/stuck lean.
​​​​​​​Any thoughts or help greatly appreciated. Cheers Dean

 

UPDATE: So I’ve still been working on this issue, and am starting to get confused. Working with a local shop (Taggart in Cary, they’re awesome,) we decided to look into the fuel tank for potential evap issues. I took apart the interior and located a hatch for the fuel tank. I had the shop inspect and replace any hoses and see if there was anything to note. All they found was one hose that was loosely attached with a hose clamp that had fallen.

After replacing this no significant change happened.
The only thing to note is that the car allows me to fill the tank to full now, before it would only do 9/10ths. additionally the stuck rich/lean code is only on bank 1, where bank 2 is just lean now.

I then chased down the next possible culprit, the MAFs. I knew some oil had gotten into the airbox from the PCVs, so that was a strong candidate. The air filters looked decent, not bad enough to be causing my issue. I removed and cleaned the MAFs they were pretty dirty, to the point where they look new. After installing them back in and starting the car, it resulted in: you guessed it, no change. At this point I’m not even frustrated anymore, just confused.

A new development now is that it is now stalling out while idling in Park while warmed up. It only seems to do it while being scanned with the scan tool, this could be a coincidence. When started back up it’s just back to the usual and does not shut down, but does leave residual codes that are AM specific, like for the throttle body, CAN bus for the transmission and PRNDL, etc. The codes only appear when it stalls out. The stalling is not consistent.

I’ve been trying to drive it more and adding sea foam to see if that helps, maybe she just wants to be driven, but after half a tank, no change.
​​​​​​​
Things to note

• It has new spark plugs and coils
• It has new intake manifold gaskets
• new O2 sensors
• new PCV valves
• new injector o rings
• The misfire is only at idle now, no longer while driving (although it does hesitate it doesn’t misfire while driving)
• the inside of the gas tank checks out, no broken hoses
• it was smoke tested and no vacuum leaks were found
• All cylinders misfire pretty equally
• The MAFs being cleaned did not fix the idle
• the cats looked great when I replaced the O2 sensors

 

Damn Clancy and I thought I had problems ​​​​​​
The only time mine misfires is when it throws the fault up, then it runs like a bag of poop. The rest of the time it's as smooth as a silkworm breaking wind.
I'm hoping for the fuel tank issue, I'm thinking that's the best of the worst and with the fuel level seemingly playing a part, it could well be.
Stay tuned.......

 

Aw man I envy you, I haven’t lost hope yet so I’ll keep updating y’all. I’m considering getting new MAFs as they’re inexpensive and there may be something wrong with the ones on the car that isn’t visible. Do you guys have any ideas on what it could be? At this point Im thinking it could be the fuel filters, or maybe some EGR or Idler air control (or something like that.)

 

Sorry buddy, I'm a newbie at this and 95% of my knowledge comes from websites like this one

 

Hello all! I was originally working on this issue with Calcifer on his previous threads way back when and I just recently got my issue fixed after several months myself by a shop by me. It took a Mercedes tech who is very familiar with Astons and 10 hours of his labor just searching down the issue but he got it done. Don't ask me how for the love of god this happened but after him searching everything mechanically (smoke test, checking fuel lines, double-checking my work, etc), he came to the conclusion of repinning the ECU altogether with the factory diagram. Car works perfect again and have had no issues now for about 3 weeks. Don't ask me how repinning the ECU worked because I'm the only other person who worked on the car and I've never touched the ECU but he claims the signals the ECU was getting were incorrect and that was the source of my issue. Just thought I would share my version of the whole Service emission issue/ stuck lean and rich issue. Good luck to all!

 

Very interesting, electrical problems should’ve been higher on my list since this is an Aston, I’ll talk to my tech about it and see what he thinks.

 

Try cleaning the grounds. There are 6 on each side for the engine harness. 6 low and 6 high. Mine were corroded. As was the ground from the torque tube to the chassis. That can generate lots of electrical gremlins.

 

I’ll definitely look into that, I appreciate it! I got in touch with an ECU place that fixes them and diagnoses them. Rather inexpensive at $250 for both ECUs. I’ll be sending them over tomorrow. I’ll keep you guys posted.
ECUs being the issue makes sense to be since when it stalls out it leaves several CANBUS codes for the engine/transmission and triggers traction control warnings and such.

 

I second the ecu. My vanquish had the same. One of the ecu/ptec was bad.

 

Hey Y’all. Some more updates. I got the ECUs back and they’re both fine with no issues found. I replaced the air filters and MAFs (the old ones looked bad.) Replacing the MAFs helped it but not by very much. I was able to update my foxwell scan tool to give me more information and got code P2139 for a faulty throttle position sensor. I’m also getting codes for the O2 sensors stuck rich. The O2 sensors are new so I don’t believe it’s that. My question is, would a P2139 code cause all this misfortune? I have cleared the codes and the code came back, so it’s an active issue. Would I be able to diagnose this by unplugging the throttle body connections and seeing if it gets better?

 

Another thing I forgot to mention. The car runs great in open loop and at or above 3k rpm. At idle and below it stutters and stumbles but at 3k rpm it’s like a switch turns on and everything works as it should.

 

I seem to be having a very similar issue.
2005 db9 - 22000 miles, with airbox delete (k&n filters). Lots of lumpyness at idle and hesitation under 3k, especially in higher gears. Above 3k like a bat out of hell.
I only occasionally get the emission service warning/check engine light. I was planning to do the coils and plugs but after hearing all your woes, I'm not sure that is the best option.
i have a foxwell nt510 Elite and am playing with the readings to determine if I can detect which cylinder is missing.
beautiful cars but sheesh they are confusing. Going to check the MAFs, throttle bodies, and fuel tank items, hopefully I can help if I find anything.

 

Hey All, so I got the car back recently from the dealer after giving up on it myself. Turns out, the fuel injector cables were swapped into the wrong banks. Truly a simple fix, probably my fault when putting it back together. I would recommend if you have these symptoms double check the fuel injector cable placement. I was sure mine was correct when the dealer asked over the phone but I was wrong clearly. The car now runs beautifully and I’m loving it. To sum up the resolution, there was a misfire when I purchased it (most likely due to the coils and plugs.) When I replaced them during putting the car back together I must’ve got the cables backwards. Best of luck to you guys if you have this issue.

 

glad you got it fixed. Waiting for the warm weather to start so I can get my DB9 on the road with the top down. Only drove it 1500 miles last year because of the pandemic. That will change this year