Right I've searched for this but didn't uncover anything. I had a 105 mile journey up to Edinburgh on Friday during which the car seemed to go in and out of limp mode(mk1 Octavia vrs) no boost limited power but then OK etc. During the journey back home the same thing but with cel light on. Got back home OK mind. Plugged my obdii Bluetooth thingy and it read p0171=power train system too lean (bank 1). Maf changed last year checked all hoses they seem fine. So being the easiest thing to do was change the coil pack ( R version for a D) fault cleared car was running great. So that should have been the end of that other than it should have been reading a misfire?. However popped up to my Skoda dealer for the 28f7 recall today with three new D version packs fitted and the same code has returned. Ive swapped packs around into different cylinders and cleared the fault but I'm just a bit confused being honest. Just wondering if any one has had this fault code before....

Possibly maf fault:

http://wiki.ross-tech.com/wiki/index.php/16555/P0171/000369

The maf does seem the obvious cause but as I mentioned this was replaced just last year(brand new genuine part). I take it bank1 means no 1 cylinder? I don't understand how changing a coil pack would solve it though. After I changed them over I took the car for a run, rescanned the ECU and the original fault had gone only to return when a new coil pack was fitted. Unless the wiring loom to that pack has gone bad?

correct me if i am wrong but bank 1 is lambda sensor ,bank1 sensor 1 is before cat bank1 sensor 2 is after cat

I think you can ignore the bank 1 part, I'm sure that refers to engines like a v6 etc where one side is bank 1 the other bank 2.

Might be worth looking on the vag-com map to see if anybody is near you.

Cheers for the help. I will have a look on there. Ran the car down to work this morning no bother all seems well right now. So can I assume bank 1 just means all 4 cylinders? Its not very specific then!!

Yeah, its not referring to a specific cylinder just that you have a fuel/air mixture problem

1.8t has bank 1 s1 front lambda sensor bank1 sensor 2 is rear after cat sensor

v6 has bank1 2 sensors the same and also bank 2 s1 and s2,as they run twin cats

OK so it looks like the lambda is picking up a weak mixture then? So any chance a faulty coil pack would cause that fault or has changing that just masked the fault?

All has been well for a few days but took the car for run today and the fault has returned. Its down on power again checked for faults and system lean is there. So when a bit of boost is required this is where the problem starts. Checked again today for any split pipes but I can't find any. The only thing I could see was the black pipe that goes into the big turbo pipe at the back of the engine had a bit of oil around the join and the original clip was loose. Changed that for a jubilee clip and the maf was changed July 2010. It couldn't be that already could it?

Have you tried cleaning the maf yet to see if it makes any difference?.

I haven't even looked at the maf to be honest just for the fact it was changed pretty recently. I think I will remove it today and give it a clean. Its the next easiest thing to do before having it checked for fuel pumps and injectors. Any ideas what to use to clean it?

Isopropyl alcohol - get it in maplins, just let it dry thoroughly before refitting.

Right, quick update. I ended up going to halfrauds and bought some egr cleaner and gave the Maf a good spray. The car has had two good runs yesterday and today scanned for faults non found. So, it does look like its been a dirty maf sensor. Although it didn't look too bad. It was bought new just under three years ago genuine vag so it makes me think how often they need to be cleaned. It only took twenty minutes so it wasn't much bother. I might just start doing it when its serviced.

Maf cleaning on the previous jap cars I have owned had almost become a 6 month service item on them to sort running issues, so it may pay you to treat it the same way after all it only costs time at the end of the day.

Egr cleaners and injection cleaners of some brands are a little bit aggressive to use on a regular basis, they can react with sealing agents on the sensor, and some spray cans are so powerful that they can dislodge the filament on the sensor itself.

A freezer bag, filled to 1/3 with IPA , then pop the sensor in for about 20 minutes, remove it from the bag, lay it on a flat surface for 2-3 minutes to air dry = job done and minimal risk.

Glad it appears to be working for you.

Kentphil1 thanks a lot for your help mate it sounds like you've had similar problems yourself? I really didn't know what to use although on e bay you can get the maf sensor spray. I would be interested to know how often Octavia vrs owners clean the Mac?

The maf?

I do my one about every 8 months, seems to be about the time it is ready for some tlc on mine.

I hope you don't think I was saying you were wrong to use egr cleaner as I wasn't, you have to do what works for you at the time to get yourself out of trouble.

It is just that experience over the years with film and element maf's on different marques shows IPA to have the least side effects, and it is quite cheap if you buy it in a large can and fill an old pump action glass cleaner bottle to use it for spray jobs.

This is the IPA stuff = http://www.maplin.co.uk/isopropyl-alcohol-28994 I use the bigger tin, I have refilled my spray bottle twice for the cost of 1 of the aerosols, still have some left in the tin as well.

This is what I put into any electrical block that I disturb on the car to seal out moisture and preserve the connections = http://www.maplin.co.uk/multi-purpose-siliconegrease-29006 I use the 50g tube, not the spray.

No like I mentioned I honestly didn't know what to use any advice is greatly appreciated. If you've found 8 months to be the time to clean it I will believe you. Mine has ran fine for over 2 years without a maf clean so I'm gonna go with a clean every service.

It doesn't throw a code or anything at that time period, it is just that the performance around town gets a bit hesitant. Since I've been using the silicone grease, you can tell the difference in the drive as against just cleaning without the grease. I suppose if you do a lot of motorway miles then you could extend the interval as presumably the crankcase ventilation system will be running cleaner for longer intervals.

Just out of interest, when did you last clean your throttle body out?

This is probably one of my problems the car does spend too much time in town and quite a few short journeys as well. I have cleaned the throttle body but time flies it was probably two years ago now. How often does that need done?

Without trying to be funny, you do it when it looks dirty, which on my one appears to be about 18 months between cleans if it helps.

Right, an update. I still have some issues. The car now isn't throwing up the original code but it feels down on power. Throttle body cleaned over the weekend maf taken off and cleaned in the alcohol as mentioned above. Now, and this is really confusing. When I unplug the maf it seems a bit better but not quite 100%. Is that normal while its unplugged or should it be perfect? Last thing, the maf was bought new in 2010. Does any one know the average life span of a maf sensor because less than 3 years doesn't seem long at all.