P2099 - 2018 Silverado

[Apadilla]

I have a 2018 Silverado 5.3 with 75k miles.  Truck runs great but P2099 code Post Catalyst Fuel Trim System Too Rich (Bank 2 comes and goes.  Have already cleaned MAF sensor, replaced O2 sensors (all 4) and recently replaced all 8 fuel injectors.  Here is the freeze frame data.

DTCFRZF	P2099
FUELSYSI	CL
FUELSYS2	CL
LOAD_PCT(%)	21.6
ETC(°С)	58
FRP(kPa) 309 MAP (kPa)  27 RPM(/min) 1302

 

VSS(km/h)	22
SPARKAD(*)	42
IAT(*C)	30
MAF(g/s)	12.41
TP(%)	22.4
02B1S1(V)	3.9

02B151 (V)	0.095
02B152(V)	99.2
02B152(V)	0.725
02B351(V)	1.6
02B351(V)	0.075
02B352(V)	99.2

 

02B352(V)	0.580
RUNTM(sec)	204
FRP(kPa)	5210.0
EVAP_PCT(%)	15.7
FLI (%)	44.7
WARM_UPS	3

 

Any diagnostics that I can do?

Edited May 10, 2024 by Apadilla

[silveradosid]

i would be checking the exhaust for any leaks. gm's are known for breaking exhaust manifold bolts

[dna9656]

Breaking manifold bolts? Just how long has GM been building engine? Do they not know what it takes in a bolt to hold up it it's application? HEY GM! let's get the bean counters out fo the design room. They are killing GM and the owners.

[rlcole321]

If you monitor O2, B2S1, (upstream) and it's cross counting good and your long and short term fuel trim are reasonably in the center, and the B2S2 (downstream) O2 is stuck at .950 or higher, then the data doesn't fit, but if both O2's are high and LTFT and STFT for bank 2 stay in the "high negative" range, then possibly fuel delivery problem (rich). An exhaust leak could cause some of these issues, but you normally see it in the fuel trim data.