Help with two codes P0173 &P1106
11-16-2011, 06:28 AM
#1
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Help with two codes P0173 &P1106
I have a 1996 Audi A4 which has an erratic idle and is very sluggish on initial acceleration. The check engine came on. Ran the codes and got P0173 and P1106. So far we have changed the driver side upstream o2 sensor and cleaned the MAF sensor. After removing the codes, they stay off for about 3-4 miles and then return generally when stopped at a stop light. Looking for help on what else my be causing the car to have these symptoms. Thanks.
P.S. The car has 105,000 miles on it.
P.S. The car has 105,000 miles on it.
12-09-2011, 11:49 PM
#2
AudiWorld Senior Member
Re: Coded message from the engine...
I did a quick check Here:
http://www.bentleypublishers.com/tec....dtc.table.htm
and note these two codes are from <i>same</i> side of the engine. I think that the 173 code is reactive, while the 1106 is likely root cause. Save for the probable air leak(s?) the car is perhaps otherwise fine. However the car may default rich and should be fixed to prevent cat damage and improve mileage and reduce emmissions.
P0173:
Fuel Trim, Bank 2 Malfunction
P1106:
O2 Sensor Circ., Bank 2-Sensor 1 Voltage too Low/Air Leak
I would look for un-metered air leaks. It is cheaper than sensors. A much discussed and searchable known issue here on the forum. Typical are crankcase vent lines, vacuum lines, noise damper to throttle-body gasket. It might be something like an injector O-ring on that side of the engine, as the code indicates. These are also searchable, see Search Forums under Forums tag at top of page.
Engine performance can be improved and faults of this kind prevented by improving measured engine vacuum at warm idle. Also searchable. These are maintenance items every owner should be aware of.
Was the replaced sensor metered to check its correct operation prior?
An air leak (into the intake stream) is a higher percentage of the total airflow at idle when total airflow is low, but vacuum is high. This is what causes it to be more noticeable; at idle.
After 3-4 miles, the car is more warmed-up and the ECM expects better mixture control by then and therefore triggers the CEL.
Some further reading:
https://www.audiworld.com/forums/sho...highlight=tour
http://www.bentleypublishers.com/tec....dtc.table.htm
and note these two codes are from <i>same</i> side of the engine. I think that the 173 code is reactive, while the 1106 is likely root cause. Save for the probable air leak(s?) the car is perhaps otherwise fine. However the car may default rich and should be fixed to prevent cat damage and improve mileage and reduce emmissions.
P0173:
Fuel Trim, Bank 2 Malfunction
P1106:
O2 Sensor Circ., Bank 2-Sensor 1 Voltage too Low/Air Leak
I would look for un-metered air leaks. It is cheaper than sensors. A much discussed and searchable known issue here on the forum. Typical are crankcase vent lines, vacuum lines, noise damper to throttle-body gasket. It might be something like an injector O-ring on that side of the engine, as the code indicates. These are also searchable, see Search Forums under Forums tag at top of page.
Engine performance can be improved and faults of this kind prevented by improving measured engine vacuum at warm idle. Also searchable. These are maintenance items every owner should be aware of.
Was the replaced sensor metered to check its correct operation prior?
An air leak (into the intake stream) is a higher percentage of the total airflow at idle when total airflow is low, but vacuum is high. This is what causes it to be more noticeable; at idle.
After 3-4 miles, the car is more warmed-up and the ECM expects better mixture control by then and therefore triggers the CEL.
Some further reading:
https://www.audiworld.com/forums/sho...highlight=tour
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