Could be your O2 sensors, dirty PCV valve or cracked vacuum hose or the coolant temp sensor which determines how warm your coolant is. What codes are you getting, P0175?

siberian

 

Banks 1 and 2 running too rich

These are the codes I've been getting:
MIL DTC
P0172 System Too Rich (Bank 1)
Stored Codes
P0101 Mass or Volume Air Flow A Circuit Range/Performance (Via mass air flow model and lambda control)
P010B Mass or Volume Air Flow "B" Circuit Range/Performance
P0172 System Too Rich (Bank 1)
P0175 System Too Rich Bank 2
P1009 Air mass meter 1/2 implausible signal from load detection

Do they make sense to you?
Thank you, by the way, for responding. It is cool to have someone to get some direction from.

 

OK 172 and 175 are the same except they refer to each bank. Since you've replaced the MAF, I would check for a clogged or dirty PCV followed by any cracks in the vacuum hoses (bit of soapy water the length of the hose will show you of there's a leak). If all that checks out, then I would clear the codes (now that you noted them) with a VAG-COM and see if it reappears.

HTH

siberian

 

Thanks, Siberian. I will do this and let you know how it turned out. Again, I am grateful. Wish me luck!

Rey

 

Get this sorted as soon as you can, or your primary cats will eventually become toast.

Subscribed.

 

thanks. I will. I hadn't thought of that.

 

I did mention checking the O2 sensors in my first post...

siberian

 

P1009 Air mass meter 1/2 implausible signal from load detection

I hope I can get some pointers. I have been working on my V8 Treg hunting down the gremlins. Changed the PCV, replaced cracked vacuum tube behind the firewall to brake booster, changed sparkplugs, replaced both MAF. Idle seems way more stable after the above replacements but notice a little rougher when I turn off the AC. Is this normal?

No more DTC except the P1009 Air mass meter 1/2 implausible signal from load detection after three days from DTC reset. What else am I missing? o2 sensor? Coolant temp sensor? Or one more slow leak somewhere?

Any pointers is appreciated.

Thanks

 

I have the same. Replaced coils, injectors, mafs's, air filters, no help so far. Crankcase vent valve is on the way, kinda confused though. Are the pcv and crankcase vent the same thing? Also, what will happen if my cats get toasted?

 

Also, would running 5w-30 oil type or 90 instead of 91 oct cause rich running random misfire and maf codes?

 

Any luck? I've replaced coils, spark plugs, maf sensors,air filters, crankcase vent valve, now about to replace the check valve. I'm very confused now, where in the hell is the pcv? Somewhere I got confused and thought the ccvv was the pcv. I need help, anything would be appreciated. These are my symptoms: I have a random misfire on all but cyl 7, and a MAP sensor code. I am burning black smoke, also have a crazy suction at the oil fill cap, misfires like crazy at low rpm, and it seems not as bad of when at higher rpm or speed.

 

I too have been pulling my hair out trying to find the root cause of this P0172 & 175!! I have a 2006 3.2L. I cleaned the MAF and throttle body (new gasket too), the code came back. I did see some cracks in the hose connectors, so I patched them for the time being with high temp insulation tape (plan to replace them if they are the cause), the codes came back. Finally, I took it to the dealer, and they noted fuel adaptation value was 11% instead of being within +/- 6%. Duh...Of course, it's high, the car is running rich. The stupid dealer charged me $150 and could not go beyond this because the mechanic found that my spark plug well gasket was leaking (which I don't think could possibly be the root cause of the rich condition). They wanted $2,100 to replace the valve cover gasket, spark plug well gasket, spark plugs, and the coils. After that, they would continue troubleshooting the root cause of the engine running rich. What a load of crap!

I replaced the plugs since they were old and half of them had oil on them. I didn't replace the coils since I have no issues with them not firing. Valve cover gasket and the spark plug well gaskets were definitely bad, they were breaking off like wood. I also replaced the intake manifold gasket. When everything got put back together, the engine was running super rough (which was NEVER the case). I heard hissing and found that I had cracked the PCV hose during the intake manifold installation (I heard a crack when I was putting the hose on but didn't register in my head at the time). Patched the crack with the high temp insulation tape while the new PCV was in transit. The rough idle went away, but the code didn't go away. Even with the new PCV, the code is with me (I didn't suspect the PCV in the first place).

According to the OBDII & Torque Pro, my coolant temp hits 195C after about 5 miles and maintains it even after an hour of driving. O2 bank 1 sensor 2 and bank 2 sensor 2 registers about 0.65V. Not getting any reading from bank 1 sensor 1 or bank 2 sensor 1, and I don't know if this is normal or not; Torque Pro doesn't show any data for them. Torque Pro turns available sensors green, but both O2 sensor 1's are black. Anyway, as far as I know, 0.65V means the O2 sensor is detecting a rich condition, but it is not the root cause as far as I can tell from all my research. The LT fuel trim is never near zero; both banks 1 & 2 hang out around -6 to -8%. The ST fuel trim will bounce anywhere between -20% +10% but hangs around +/- 5% the majority of the time. I also get these: Exhaust gas temp Bank 1 Sensor 1(°F) 382; Exhaust gas temp Bank 1 Sensor 2(°F) 413; Exhaust gas temp Bank 1 Sensor 3(°F) 497; and Exhaust gas temp Bank 1 Sensor 4(°F) -40. I don't know if I trust any of the readings, because they never change. Finally, the Air Fuel Ratio hangs around 14.8 +/- 0.3.

If my O2 sensors were bad and detecting a rich condition, wouldn't the computer compensate by cutting back on the fuel? How can I troubleshoot a bad fuel pressure regulator or fuel injectors? Has anyone successfully fixed this issue?

 

Not sure you're still around. Have you managed to find the root cause?
I have had the intermittent rich condition (-25) for a while now and never had the time to really diagnose it.
In my case it happens on deceleration. I have done some repairs and fixing of other issues and will be working on this one next.
Here is my thread. If you have any additional info you're welcome.

Touareg MK1 Air fuel Mixture issue

17499 - Mixture Regulation; Bank 2; Range 1: Rich Limit Exceeded P1091 - 002 - Lower Limit Exceeded 17573 - Long Term Fuel Trim Additive Air; Bank 1; Range 1: System too Rich P1165 - 002 - Lower Limit Exceeded I did some reading on the rosstech site. I will replace the MAF...

www.clubtouareg.com

 

I know this thread is old, but if anyone has had the same problem: Lean codes BEFORE a repair (IE replaced MAF sensors, fixed vacuum leak, etc) and now have rich codes AFTER said repair, you need to reset adaptations for the ECU, not just clearing the codes.. You will likely need to go in with a scan tool with this capability and have this done. I hope this helps someone.

 

I have had both rich condition and then lean condition on a 2004 v6 petrol and I fixed both issues: rich condition with vac hoses repair including brake vacuum hoses the. The lean condition with a new secondary pump. I only had to reset the engine fault codes. You can do without the fault code resets as it they reset themselves after a long trip. The codes are long term fuel trim codes so you need to drive a good amout of miles for the ecu to do the calculation and once the values go back to what is expected (generally around -5/+5) codes will go away. -25/+25 is when the error code is triggered. +25 for lean and -25 for rich. I have other threads where I explain the lean condition linked to weak fuel pumps. Will put a link here later.