System Lean and Misfires?

Thank you, Joe.

I did use OBD2 and VAG keeps in my car every time when fault occurs doing the scan too. System gets misfire codes multiple or random. And lean condition every time. I do delete these codes usually. Sometimes this code went off itself and returns back after couple of days together ECS light is on. I am sure it's not related to vacuum as its the engine whole time not acts this same issues. If there are vacuum leaks from hose, gaskets etc. It should be permanent not intermittently. So, the engine will be always misfire. But in my case it happens only sometimes. Especially in turning, first start up, low speeds, shifting tracks etc. And when I stops the car and restarts the misfires went of itself. So I am sure its not related vacuum leak. As you said it ma y be a chance for fuel pump as the fuel pump overheating sometimes this may occurs. Not sure. Buying fuel pumps pair for touareg models are cost up to usd 500 in Kuwait. I also guess for oxygen sensor related issues it will be cost up to same dollars. So I am totally confused to replace it with the fuel pump or Ox first. Thanks again.

Thank you for your reply. Its reading 0.470V like this in idle. And fluctuates. I am not sure what the voltage in highway running. But I'm sure it's not exceeding more than 1 volt ever. So, hopefully O2 are fine. 3days it was running very worse. But yesterday and today morning I feeling it running like a champ. No misfires. TCS was not present on these three days, but today it came again while at highways. I am sure the TCS is related in this misfire issues. Sometimes I am getting MAF sensor code also. Hats reason I did replaced those sensor. TCS light went away for 1-2 weeks but again came back with lean condition codes. And one more think. When I am shifting the tracks at highways the engine losing its power sometimes and when decelerating and after pressing on gas pedal its developing speed as normal. It feels sometimes on u turns also.

Thank you, Ken. I did replace MAF sensor 2 months back because of this issue is existed since 6 months. Tried several options. Throttle body and ignition coils replaced. Leaks in intake pipes and brake boosters rectified. Felt little improvements for a week or maximum 1 months. After again begins the same issues. Then after replacing spark plugs it was fine for last 1 month but again the lean condition started and I noticed the OBD scanner throws MAF sensor Code P101 together lean condition code again. I doubt it was seeing last time after I filled gas full tank. After 3 days when the gas level gauge goes below 3/4 tank it have some improvements. The 2 time restart is no need now every days but required occasionally and when I came to car and turn the ignition to acc and sudden to start stage its acts misfire and its continued till next restart even drive 1 hour or now. But if I wait for a minutes after acc before starts it seems fine. No more misfire and car runs at super speedy, It's my guess but not sure. I think this is something fuel pump priming issue or there any fuel delivery issue s. This engine have head cover gasket leak before so I did replaced and for a month it was fine. But after a month it again starts leaking oil in spark plug wells of cylinder 5 and 6 causing coils to get flooded occasionally. So, I its my routine check up to clean these spark plug wells 2-3 months gaps. And the previous owner of this car was deleted the PCV valve in intake manifold and closed, then vented open the breather hose coming from crankcase. I did connect this PCV with breather hose 2-3 times but failed due to high pressure forming inside the crankcase and causing oil to escape from other sides like head cover, oil pan etc. But when the hose from crankcase in open vented mode, there is no more pressure and oil leaks except the head cover gaskets.
Thanks again for your patience.
Have a nice day.

Dear Jacob,

Because of this lean condition, TCS and p101 code, 2 months I replaced this sensor after it was fine for a month. There after this P101 code does not stay always. It comes sometimes weekly once with TCS light on and went off itself after 10 or 15 minutes and returns back later a week or so. Technically the TCS light is very closely related to P101 Code in these Touareg models. So, I guess MAF is still fine. Yesterday morning I noticed that the engine wouldn't turn on at its first attempt. It's trying to kick starts but fails. After I removed the key out and tried to start again but started with some hesitates. After returning to home at evening came to car its having same issues. Today morning its started fine and I went to outside for some office related, the engine wont starts at first attempts after each stops. Its just attemping the starter motor but not starts. But second tiime its starts but little hesitates again. No TCS lights. After all its riding fine but in taking to another tracks at highways its hesitate its speeds. Struggling acceleration, loosing engine power etc. I guess its fuel pump is the culprit but in technically I read about that in such types of cars have a safety features that when a misfires/over heating/mechanical failures occurred in engine/transmission case the ECM will detect an emergency situation and will cut off the fuel supply to the Injectors. If this is right, I guess the fuel pump may be Ok but there is some mechanical issue in the engine or any sensor related. Its because engine does not always showing the same troubles but eventually. What to do no idea. If its fuel pump fault I am ready to replace but the safety features as I said above it will be totally loss.

Hi Brother. Thanks.
From 2 days the starting issue is solved over itself. The fuel level is below the half tank now. Car starts fine at every stops even morning at first kick without any hassles but in running at above 40km/h at highways, turning to another track or entering to main roads from pocket roads I mean while turning steering wheel or taking U turns the engine feeling low power and stalling. After getting the steering wheel steady it runs again fine. Air bag faulty light is completely turned on from 3 months. Never turned off. TCS light came on once a time within these 2 days but went off itself after restarting and ride. This car has a steering wheel angle sensor intermittent signal trouble code also. Is this steering wheel trouble code from ECU sends signals to engine to stall for fuel pump to cut off?/ If yes I believe this is the main culprit.

Hi Jaco,

It's P0778 code from VCDS scanner. No, the engine doesn't have any power loss while sitting but have while taking U turn or shifting to another track but it's not always. It happens sometimes only. And the same scenario while accelerating. Acceleration is smooth at normal driving but sometimes in sitting when I press the gas pedal The RPM going smooth above 1000 rpm and returns back as usual but after engine jerking and drooping to nearly 500 RPMs then it comes to normal as 700 RPMs. It's too not always but some occasions.

Hi Jacob, it's P0778 code from VCDS Ross tech VAG scanner. This code may wont available in OBD2 code list. I have photo of this code took from my laptop on jpg format but can't upload it. The page says the filetype not allowed.

Hi Jacob this is the link. This site is about to VCDS group of cars and code about steering wheel angle sensor http://wiki.ross-tech.com/index.php/00778

I too have transmission fluid pressure sensor range fault code also, but the transmission is fine always. No issues.

Hi brother. Unfortunately, these type of scanners wont available here in local market nor with mechanics. Only with VW authorized dealer uses I guess.I seen all mechanics using here VCDS only.

Hi,

Now my thought is something related to fuel pressure. So before Yesterday I removed the EVAP purge valve and closed the vacuum hose from intake manifold with a bad plug. The power harness kept disconnecting. Kept the EVAP hose from fuel tank vented open. After driving there feels something different. The TCS light went off and hasn't come back yet in the last 2 days. The car runs fine but having little struggles at same track shifting. Same for Starting issues too. But much better than before. All over the car runs fine now. I guess the fuel pumps may be struggling to operate as the pressure is being trapped inside the fuel tank and it's not vent off due the purge valve stuck closed. Didn't open at time. It's my guess.