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First off, apologies for the looooong post. I have spent approx 30 hours researching this and have found masses of conflicting threads posts and resolutions hence why I am now posting my own thread after getting seemingly nowhere. I have added my full auto scan, with Advanced ID and the Log I took yesterday as attachments to this post. Backstory: I purchased a 2007 A3 Sport with BMN PD170 lump back in March after my PD130 MK4 GOlf was written off. Other than a few niggling issues that were easily resolved (passenger door mech, ignition switch, oil level sensor, brake pad sensor etc) the car was faultless and drove perfectly. No smoke, no drivetrain issues, no electrical gremlins. It was perfect. Issues: Then, in late April, as the weather started getting warmer, air temps above 15/16 degrees C, the car starts to hesitate between 1400 & 2000 rpm. Once you've passed 2krpm, it's fine and pulls hard. Once the car is warmed up, it generally does not happen. Researching this issue there seems to be a lot of disagreement on any forum over what the problem is. Some people swear it's the DPF, others the MAF, others the EGR valve, others say it's the EGR cooler and some claim it's the DPF pressure sensor. Approx a week after the hesitation first started I got an EML. VCDS showed it was a lambda sensor issue. No problem, several hours of research later (it transpires the BMN uses an NTK sensor, not a Bocsh unit like every other VAG ever made?!?) and I got a new one fitted in under 40 minutes. Took it for a drive and no more hesitation. I put this down to the faulty o2 sensor preventing a DPF regen as its was only reading a static value. For the next couple of days, the car drove faultless again. About 3 days later, the hesitation returns (turns out the ambient temperature had been a little cooler). Logging the o2 sensor, I confirmed that it was working as it was reading the AFR values and no more error codes have been logged in the 3.5 months for the o2 sensor. At this point, the hesitation has become more of a lurching or kangarooing, again, only between 1400-2000 rpm. I have also done the following in an attempt to remedy the issue: Cleaned the MAF with electrical contact cleaner - Did not resolve the issue Cleaned the egr valve & ASV (this was horrendous inside) - Did not resolve the issue, though it was better yesterday Checked the intake connections - nothing loose or unconnected Verified the boost specified vs actual - at all measured rpm's the spec/actual are almost identical, especially in the trouble range of 1400-2000. This would rule out a boost leak as is common. Measured the MAF readings - approx 200mg/str at idle and rise to approx 450 at 2-2500 rpm - I'm not sure if this is right or not but I have had MAF issues on my old PD130 and it was noticeable through the entire rev range as a considerable lack of power - this is not happening here as I have loads of power after 2krpm. Full fluid and filter service with new fuel hoses from the filter to the hardlines to the cylinder head (perished). Logged the EGR duty, In addition to the above, I have also taken logs of the DPF and this is where I start to scratch my head as I'm just not sure what is going on here. The Particle Filter - Load Coefficient: this was at 0 for approx half of the log session, then jumped immediately to 20% and didn't budge. The Particle Filter - Carbon Mass: reads 22.23 for the entire duration of the log (20 minutes) The Carbon Mass - Learned Value: this was at -7.9 for the entire drive/log session. Would the above be indicative of the DPF differential pressure sensor being problematic? I did look at it yesterday, and it appears someone has been in there before me as the retaining bolt is missing. I've not checked to see if it's a genuine or non-genuine item, but if the above readings are symptomatic of the DPF pressure sensor, then my assumption would be that it was never adapted, or that is a cheap crap one that has failed? Does this sound right? The only error code I get is the one below: 008194 - Particulate Trap Bank 1 P2002 - 006 - Efficiency Below Threshold Again, there seems to be a few trains of thought as to what this actually applies to but generally most agree it's either DPF (differential pressure sensor) or EGR cooler. I do not suspect the EGR cooler as being at fault as the Exhaust Gas - Recirculat. (spec.) & Exhaust Gas - Recirculat. (actual) are fairly close. I have added a table below with a snapshot of the log I took yesterday. Based on further up I would suspect this code is related to the DPF pressure sensor in my case, would anyone else agree? My main theory at the moment is that the DPF is failing to regen, and at lower exhaust pressures, it's causing the hesitation. As soon I am over 2krpm, there is enough positive pressure to overcome the dpf restriction and it drives fine? My secondary theory is that the EGR tends to shut over 2k rpm, and it is the EGR flow that is causing the issue (either too much or too little recirculated gas). Though since cleaning the EGR the issue still persists and I can see the EGR duty fluctuating over 2krpm in the logs. Does anyone have any further insights or recommendations? AdvID_AO57PZY-WAUZZZ8P08A059569-135306.txt AUTOSCAN_AO57PZY-WAUZZZ8P08A059569-217750km-135303mi.txt LOG-01-011-03E-418-687.CSV

Audi S3 2019 Sportback 5Dr (Stock) 40k miles. Hi all, have been having this issue with my car for a few months now. Seems to hesitate when flooring it at 2,800/3000 rpm + and when in 3rd gear onwards. Initially thought Spark plugs may do the trick. This was recently changed - and on the same day my brother in law had connected his diagnostic kit - it came up with a fault code re o2 sensor bank 1 sensor 2.. he had cleared that for the time being and taking it to two garages (including 1 VW/Audi Specialist), we haven’t been able to replicate the fault code and the specialist couldn’t insist more that it’s not the o2 sensor and that could have flagged up even from a bad batch of fuel. They recommended I take it somewhere with a dyno system which may help to identify the issue? I’m so lost as to where to go from here. My brother in law who are somewhat better clued up on mechanics than me are now suggesting changing the coil pack. Last full service was March 2022. Minor service 2023. Both from main dealer. We do do ALOT of miles. Any suggestions? Thanks in advance IMG_9283.MOV