1998 CL600, 84,000 miles owned since April. Friday the CEL came on with P0170 - Fuel Trim (Bank 1). At the time I had only a simple OBD2 reader. I cleared the code and the CEL remained off. On Sunday I purchased a better OBD2 scanner that can read live data. Sunday evening I noticed that I have a pending P0170 code. This morning I swapped the two MAF sensors thinking if one of them was the problem the code would switch to Bank 2. Today at lunch the CEL came on again with P0170. The scanner read the following freeze frame. I also captured some live data after the light came on. The car is running very smooth at idle and strong during acceleration. Two things that I'm concerned with are the engine temperature (212F) and the manifold pressue (12.9 inMg). Shouldn't the vacuum be higher? Most cars I've had before are at 18-20. Tonight I'll attach a vacuum gauge. The car is running very smooth so I'd be surprised it had a vacuum leak.


Freeze Frame Data

Fuel Sys 1 CL
Fuel Sys 2 CL
Calc Load(%) 16.8
ECT(F) 212
STFT B1(%) 3.9
LTFT B1(%) 0
STFT B2(%) 0
LTFT B2(%) 1.5
MAP (inHg) 12.9
Eng RPM 525
Veh Speed(mph) 0

Sample Frame of Live Data (after CEL came on)

Fuel Sys 1 CL
Fuel Sys 2 CL
Calc Load(%) 19.2
ECT(F) 212
STFT B1(%) -6.2
LTFT B1(%) 2.3
STFT B2(%) 0
LTFT B2(%) 0
MAP (inHg) 15.6
Eng RPM 1173
Veh Speed(mph) 9
Spark Adv -19
IAT (F) 105
MAF (lb/min) 3.026
TPS(%) 6.6
Air Status OFF
O2S B1 S1 (V) 0.780
STFT B1 S1(%) -3.1
O2S B1 S2 (V) 0.685
STFT B1 S2 (%) NA
O2S B2 S1(V) 0
STFT B2 S1(%) 0
O2S B2 S2 (V) 0.770
STFT B2 S2 (%) NA