New Battery - now having misfires

[breezy2087]

I have a 21 ST (62,000 mi - no mods/aftermarket parts) that I had to swap the battery on. Wasn't aware of the BMS so I drove my car on after swapping the battery. After I traveled about 45 mins on the insterstate, I got off and under low loads <2500 rpms, I started hearing this odd clattering noise. I know that the cross pipes can start to make noise at the accordians, so I thought maybe it was my time and I'd check it the Friday after Thanksgiving. I woke up the next morning and drove the car on the interstate another 40 mins - no issues while on the interstate. I get off on my exit and all hell breaks loose. I've heard rod knock and valve clatter before, which is what this sounded like. I had about a mile and a half to my destination, so I limped the car there and parked it. My oil pressure light came on during the limping. I checked my oil and it was pretty low, so I added oil. Then while running the car, the noise lessened a bit but my CEL came on and started throwing codes:

• P0300 - RANDOM/MULTIPLE MISFIRE (CONFIRMED)
• P0304 - CYL 4 MISFIRE (PENDING)
• P0305 - CYL 5 MISFIRE (PENDING)
• P0306 - CYL 6 MISFIRE (PENDING)
• P0019 - CRANKSHAFT POSITION - CAMSHAFT POSITION CORRELATION BANK 2 SENSOR "B" (PENDING)
• P054B - COLD START "B" CAMSHAFT POSITION TIMING OVER RETARD BANK 1 (PENDING)
• P054D - COLD START "B" CAMSHAFT POSITION TIMING OVER RETARD BANK 2 (PENDING)

I reset the BMS the next day later in the evening, according to the manual, after replacing the battery it states it needs 8 hours of "sleep" but doesn't specify if that is after swapping the battery or resetting the BMS.

I'm hoping this is just an electrical hiccup - not looking forward to swapping plugs/and boots around to troubleshoot.

 

[SlowSTExploder]

If the low oil pressure light cam on, than the cam phasers went dry... you might have a bigger problem now than just spark plugs and coil pack boots

 

[wifeys-ST]

I was under the impression that if you reset BMS you don’t need to wait at all to drive. But if you replace the battery, and you let the car sit for 8 hours it will automatically reset the BMS for you. could be wrong but i’m pretty sure of that.

The engine issues are not related to the battery but it doesn’t hurt to unplug the battery and wait 5 min and reset. Is it possible you got bad fuel?

how did you check the oil level, these engines are easy to misread.