Chasing Codes (no solid resolution yet!)

[HoneyBadger302]

I have a 2011 Silverado 5.8 LT with approximately 189,000 miles.

 

After a (every single one) fluid changes at a local shop (I'm sure unrelated, but just in case), I started getting and have been chasing random codes, centered around Run Rich, O2 sensors, emissions, and injectors. Only ever 1 or 2 codes at a time, but as I've replaced parts, the code would jump to some other random code(s) I'd get a couple times, then with the next replacement, would change to something else!

 

With the mileage, I decided to change out a bunch of stuff since most of it was probably overdue anyways. Thus far I have replaced the: charcoal canister; evap valve; battery; O2 sensors (one of them twice); spark plugs and wires; alternator (unrelated); cleaned and tested the MAF sensor; and ran through some injector cleaner on a few tanks of gas.

 

The most recent code was P214a IIRC, first time for that one though. None of the codes have been consistent, either, especially since replacing everything. Both banks, this bank, that bank, swapping around, ZERO consistency. Tried disconnecting the battery for a day, no codes for over 2 weeks (I don't drive daily), but this last one popped up this weekend. I tried clearing it, nothing on the 2 hour drive home, or on my commute yesterday.

 

I hate to go spend a ton of money having someone else chase this problem in circles, but about all that's left are ECM, injectors, or cats taking a poo on me (or some random wire short somewhere).

 

Anyone else had this and found some specific things it could be before I end up spending a ton of money to have someone else chase things?

 

Oh, and this entire time, my gas mileage has been great. At first it had some rough starts/rough idle when starting, but after changing the O2 sensors that went away completely. No other run, power, etc issues. I'm at my wits end with this...the remaining items are a bit more complicated to deal with (and/or costly).

Edited June 12, 2024 by HoneyBadger302

[asilverblazer]

Each code will have a specific diagnostic procedure associated with it. Some codes indicate a problem with a sensor and require a sensor replacement. Some explain a condition that a sensor is seeing a problem with something else and the sensor is fine and shouldn't be replaced.

 

Further, there is a common thought here that aftermarket sensors are inferior to factory, I'm not sure how often there have been documented cases of that actually being the case but it is also a possibility. 

 

The PCM expects to see very specific readings from its sensors and surprises or abnormal readings are going to cause problems, changing parts that aren't broken or replacing parts without a diagnosis can thus introduce new problems on top of the old ones - proceed with caution.

 

Confirm the current code.