First major engine problem

[MOCamaro]

Hello all,

I have been a member here since 2009 and have benefitted greatly from the many, many excellent discussions regarding maintenance and upgrades. I haven't posted much because everyone here always has so much more experience and knowledge than I have that I never seem to have much of value to add. What I haven't needed or had to offer is repair advice because this car has been bullet-proof...until now (15+ years and 135,000 miles later). Truly, not one thing has gone wrong with the car in all that time.

The other day though, when I slowed for a stop sign, the engine suddenly stumbled, lost power and would barely keep running. I was literally a block from home and made it there but when I got out of the still-running car I could hear it pinging/knocking like crazy and the strong smell of gas told me the ignition was waaaay off. Typically for a misfiring engine, the Stabilitrak warning was also on the DIC.

I grabbed my code reader and it showed U2100 (CAN Bus Communication), P0174 and P0171 (both banks too lean) and P0300 (random-multiple misfires)...and that's all.

I have been searching and searching and haven't seen any discussions of this particular combination. Notably, it's not throwing any codes related to the camshaft and crankshaft position sensors. Also, I have looked high and low for broken connections and wires and have found nothing. I also checked the ECM for circuit continuity and the running voltage and they are good. Finally, all of the body systems (lights, locks, HVAC, etc.) are working fine so I don't think there is a BCM problem.

So, any thoughts? Am I at the point of checking for resistance one controller at a time to see if I'm staying in the 60 ohm range? Would the car run at all if the ECM was indeed dead?

Is this one of those times when a tow truck to the repair shop is the best option?

I will greatly appreciate any suggestions you have!

Paul
St. Louis, MO