Limp Mode (Bank 1 misfires and Air Injection System)

[335m]

Went to start up the car yesterday and got my normal cold morning rough start but it got significantly worse and ended up tossing the car into limp mode.

CODES:
P0172 (Secondary Air Injection System)
P0300 (Random Misfire / Lean?)
P0301 (Cylinder 1 Misfire)
P0302 (Cylinder 2 Misfire)
P0303 (Cylinder 3 Misfire)
P0304 (Cylinder 4 Misfire)

So I believe the two most possible issues here could be my battery going bad (500/900 CCA on original battery), or my bank 1 pre-cat O2 sensor is going bad.

First step of diagnosis will be to swap my pre-cat O2 from passenger to driver and see if the codes move to bank 2.

Any other recommendations?

[8600RPM]

It's your precat 02. JUST had same codes this week and dealer changed precat o2.

[335m]

Update: Swapped passenger and driver's side precat sensors and the car started up perfectly. Previously it would go into limp mode and misfire before being completely warmed up.

So I will be purchasing 2 new precat o2 sensors. (even though passenger is most likely the bad one)

[335m]

Okay I installed the new o2 sensors precat but now I am receiving the following code even after clearing and driving for a while...

P2096 - Post Catalyst Fuel Trim System, Too Lean Bank 1

[8600RPM]

Post cats? You sure it's not vkat? Which is pre cat

[vsix]

Originally Posted by 335m

Okay I installed the new o2 sensors precat but now I am receiving the following code even after clearing and driving for a while...

P2096 - Post Catalyst Fuel Trim System, Too Lean Bank 1

Its about time to get rid of the good ole batt.
Can you life log?
If so please do an life log session...I might have an idea but first I need to see your values!
For anyone else reading this, dont buy such parts because of the dealer mechanic "suspects/ claiming" an faulty part unless you or him are 100% sure.
That way alot of "good" mod money goes down the drain.

I once was in the same position!
Dealer claimed an faulty 02 sensor that needs to be replaced no way around, at the end my O2 Sensors were acting up yes BUT
( saw that over the life log session )
then INSTEAD of buying new sensors I just swapped sides left with right
( as suggested by an certified Carly mechanic from munich )and with this swap I revealed that only the 02 connectors came loose and my 02 sensors werent faulty!
Buying a new battery, as mentioned does also wonders.

[335m]

Originally Posted by 8600RPM

Post cats? You sure it's not vkat? Which is pre cat

Well I just replaced my pre-cat o2 sensors with new ones, maybe I didn't tighten them down enough or the connector is loose.

Originally Posted by vsix

Its about time to get rid of the good ole batt.
Can you life log?
If so please do an life log session...I might have an idea but first I need to see your values!
For anyone else reading this, dont buy such parts because of the dealer mechanic "suspects/ claiming" an faulty part unless you or him are 100% sure.
That way alot of "good" mod money goes down the drain.

I once was in the same position!
Dealer claimed an faulty 02 sensor that needs to be replaced no way around, at the end my O2 Sensors were acting up yes BUT
( saw that over the life log session )
then INSTEAD of buying new sensors I just swapped sides left with right
( as suggested by an certified Carly mechanic from munich )and with this swap I revealed that only the 02 connectors came loose and my 02 sensors werent faulty!
Buying a new battery, as mentioned does also wonders.

I'll try swapping out the battery, not sure how to take a life log. I have the torque app with a BT adapter.

[vsix]

Originally Posted by 335m

Well I just replaced my pre-cat o2 sensors with new ones, maybe I didn't tighten them down enough or the connector is loose.


I'll try swapping out the battery, not sure how to take a life log. I have the torque app with a BT adapter.

Sorry my bad, thought you use the Carly ( former BMWhat ) app.
Nevermind!
Yeah first swap the battery and we'll go from there!

[335m]

Just updating in case others run into similar issues and come by this thread.

Replacing my precat O2 sensors and my battery got rid of all my codes. I have driven around 150mi since installing the battery and O2 sensors but I still have some incomplete monitors. (O2 and secondary air I believe)

I highly recommend purchasing O2 sensors through Amazon, and I got my AGM battery at a local AutoZone for less than $200. (Register it or disable the smart alternator stuff)