Low idle 500 rpms, vibration at idle

[sticks]

First thank you for everyone's assistance. This forum has been great in diag and mods to my tahoe. Today I need to think through an idling problem. It has a vibration in the truck and steering wheel at idle. I've never had it die on me, but it idles very low. 400rpms to as high as 1100rpms. I have one code P0171, and now a new one, P0300. Those are Bank 1 too lean and Random/Multiple Cylinder Misfire respectively.

I have cleaned the MAF and inspected the engine for vacuum leaks. I'm concerned I'm looking at an intake manifold gasket.

Below is my freeze frame data:

DTCFRZF P0171
FUELSYS1 CL
FUELSYS2 CL
LOAD_PCT(%) 30.2
ECT(F) 194
SHRTFT1(%) 54.7
LONGFT1(%) 25.0
SHRTFT2(%) 6.3
LONGFT2(%) -6.3
MAP(inHg) 14.2
RPM(/min) 554
VSS(mph) 5
SPARKADV 18
IAT(F) 104
MAF(lb/min) 1.167
TP(%) 11.4


This is my live data:
DTC_CNT 1
FUELSYS1 CL
FUELSYS2 CL
LOAD_PCT(%) 36.5
ECT(F) 194
SHRTFT1(%) 0.0 to 2.3
LONGFT1(%) 1.6
SHRTFT2(%) 0.0 to 2.3
LONGFT2(%) 0.8
MAP(inHg) 11.8
RPM(/min) 799
VSS(mph) 0
SPARKADV 18
IAT(F) 135
MAF(lb/min) 1.393
TP(%) 13.7
O2SLOC B1S12--B2S12--
02B1S1 (V) 0.015 to 0.695
SHRTFTB1S1 (%) -2.3 to 0.8
02B1S2 (V) 0.660 to 0.700
02B2S1(V) 0.075 to 0.655
SHRTFTB2S1(%) -0.8 to 0.8
02B2S2 (V) 0.640 to 0.665
OBDSUP OBDII



Any thoughts? Any tips on how to rule something out, or confirm it's the gasket?

Thanks

 

[lowflyer]

bank 1 LTFT and STFT look like you have a massive vac. leak on that bank. Are you sure that the LTFT is at 54%? I didn't think it would fuel any more than 25%. Anything more than that and fuel control is out of control. All this points to a manifold gasket leak on that side. This is also supported by the P0171 code.

Also, when driving, watch or datalog the Engine Load %, make sure that when you floor the vehicle from a roll, the % goes above 80-85%. If it doesn't the MAF is not reading correctly. But in this case, I don't think the MAF is the problem because the imbalance is only on the 1 side and not on both.

As a side note, make sure the fuel pressure is OK. Usually this affects both banks, but I've seen one side more sensitive than the other before.

Good luck and keep us posted.

 

[ID_Escalade]

I had the same problem with mine, it had the miss fire code and was idling really rough and i looked under the hood and one of my spark plug wires came off