Hit a deer, now engine is running lean

[zach1990]

About a month ago I hit a deer at roughly 50mph with the front driver side. Pushed in the bumper, knocked the lights loose, and snapped the PCM housing loose. Fixed all that but it's constantly throwing a code for engine too lean (bank 2). I've been clearing the code out for a few weeks thinking it may be from the combo of my cold air intake and cold mornings but its back with this warmer weather. The only thing I've noticed since this code came up is that the engine runs very rough idling until it warms up. My question is what should I be looking for to remedy this? I've searched around under the hood but I don't see anything immediately obvious.

[mike94silverado]

I take it this wasn't a body shop/insurance repair?

[zach1990]

Nope. I do everything I can on this old thing myself. Always have

[zach1990]

I am referring to the 2000 Sierra in my sig btw. Sorry for not posting that part

4.8 4L60E 4x4 rcsb SLE

[&CDFiXER%]

Knocked a ground loose somewhere? Pulled a wire loose/out of the PCM harness?

[zach1990]

Not that I noticed. Ill look it over some more tomorrow when I've got more time

[MikeNH]

Did the deer damage an O2 sensor?

[zach1990]

Hmmm it did roll under the truck and I didn't think of that. Ill check that too

[Btuggle88]

Sounds like O2 sensor and it could just be bad timing on its demise. If it's throwing a code it probably is a sensor.

[zach1990]

Ill definitely look into it in the morning

[Doug_Scott]

Take a look at vacuum lines as well. Are there any lines around cannister that could be damaged? Keep in mind that a deer is not just a chunk of meat, it has appendages that can reach 2 or 3 feet further and in more directions than you may think.

[zach1990]

Ok so no vacuum leaks, could not find any loose or damaged wires, MAF sensor is clean, PCV is functioning correctly, and the wiring to the O2 sensors is fine. Now it's showing lean in bank 1 and 2 as of this morning so ill guess ill replace the downstream sensors and go from there.

[bossier62guy]

How about posting the codes....

[zach1990]

How about posting the codes....

PO171

PO174

[bossier62guy]

Check your fuel pressure....this may not have a thing to do w/ the deer.