eswaroop wroteAn improperly registered battery may be over charged and damaged over a long period of time leading to premature failure. Failing battery can lead to all sorts of weird electrical issues and confusing code combinations.I’m curious why do you ask about the battery ? I have similar code and battery was not properly registered prior - what’s the relation ?
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Update to my original misfire issue:
So oil level correction fixed the problem initially. However, after a while, the misfire came back. I got similar set of codes to deal with. Basically, it is complaining about Oxygen sensor of pre cat and misfire of bank 2. Since the oxygen sensors have been replaced, i decided to replace secondary air injection control valves. That was the only logical direction I could think of.
To share briefly on the process, it was very painful to replace them on either size. I followed forum recommendation to buy smaller wrench which isn't to helpful in my case. On the bank 2 size, i took off exhaust heat shield which helps a lot to get me some room to access the valve's lower nut. Also MOST IMPORTANT, i removed the transmission mounts (was to replace shift linkage seal) and was able to lower the engine down a bit (tiling downward). The engine sat on engine mounts only without transmission mounts. Engine mounts became pivot points. By doing so, I was able to gain just enough space access the nut. Off course, you need to remove lots of wiring harness and secondary air duct etc. I also used borescope to check on the air channel condition. It is a bit dirty but not too bad. (Anyway)
So in the end, after replacing the valves and use seaform to clean the air channel. The bank 2 misfires did go away. At least after about 500 miles, it is still fine.
However, fix wasn't perfect. the car still has three codes but NO check engine light ON.
27B1 Secondary air system flow rate bank2
2729 O2 sensor coast mode diagnosis before cat
2743 Oxygen sensor heater resistance diagnosis before cat
I drove my car for about total 400-500 miles and was not able to clear the code and was not able to PASS SMOG (CA). Engine seems to be fine and no misfire.
In the end, i took my car to local Indy Shop (Motorspeed West) and asked for help. Initially, they thought it was bank2 O2 sensor but after swapping left to right. It didn't help. They checked the O2 sensor wiring to DME resistance. It was also fine. They also reseat connector at DME side. They also drove the car for 30 miles through speed sequence in order to clear code. In the end, somehow, the code went away. (I am not sure if code got cleared by tool or by driving at sequence speed). They get my car SMOG at nearby SMOG shop and passed.
To this day, i am still not sure that true cause of bank2 misfire. (Possible cause: O2 sensor, Oil level, secondary air valve). For now, it seems to be gone.
So oil level correction fixed the problem initially. However, after a while, the misfire came back. I got similar set of codes to deal with. Basically, it is complaining about Oxygen sensor of pre cat and misfire of bank 2. Since the oxygen sensors have been replaced, i decided to replace secondary air injection control valves. That was the only logical direction I could think of.
To share briefly on the process, it was very painful to replace them on either size. I followed forum recommendation to buy smaller wrench which isn't to helpful in my case. On the bank 2 size, i took off exhaust heat shield which helps a lot to get me some room to access the valve's lower nut. Also MOST IMPORTANT, i removed the transmission mounts (was to replace shift linkage seal) and was able to lower the engine down a bit (tiling downward). The engine sat on engine mounts only without transmission mounts. Engine mounts became pivot points. By doing so, I was able to gain just enough space access the nut. Off course, you need to remove lots of wiring harness and secondary air duct etc. I also used borescope to check on the air channel condition. It is a bit dirty but not too bad. (Anyway)
So in the end, after replacing the valves and use seaform to clean the air channel. The bank 2 misfires did go away. At least after about 500 miles, it is still fine.
However, fix wasn't perfect. the car still has three codes but NO check engine light ON.
27B1 Secondary air system flow rate bank2
2729 O2 sensor coast mode diagnosis before cat
2743 Oxygen sensor heater resistance diagnosis before cat
I drove my car for about total 400-500 miles and was not able to clear the code and was not able to PASS SMOG (CA). Engine seems to be fine and no misfire.
In the end, i took my car to local Indy Shop (Motorspeed West) and asked for help. Initially, they thought it was bank2 O2 sensor but after swapping left to right. It didn't help. They checked the O2 sensor wiring to DME resistance. It was also fine. They also reseat connector at DME side. They also drove the car for 30 miles through speed sequence in order to clear code. In the end, somehow, the code went away. (I am not sure if code got cleared by tool or by driving at sequence speed). They get my car SMOG at nearby SMOG shop and passed.
To this day, i am still not sure that true cause of bank2 misfire. (Possible cause: O2 sensor, Oil level, secondary air valve). For now, it seems to be gone.
