Majorshelton
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- Thread starter
- #1
I have a 2020 JTR and stupidly put a Magnuson Supercharger on it. Replaced the motor last year after a rocker wheel broke off and chewed the cam lobe down. A few months ago, the supercharger seized up and caused the engine to eat it. I rebuilt the whole top end, replacing all 24 rockers and lifters as well as the two intake cams. Returned the engine to stock and flashed the factory tune back onto it (did that myself using HP Tunes). I got catalytic converter codes and replaced the passenger side. The driver side did not fit properly, so I have a new one on the way.
I am now getting false Rich Fuel codes for both banks. I say false, because the fuel economy it is reporting is double the actual mpg. Example, it is reporting 26 mpg when it is really only in the 13 to 14 range.
My hypothesis is that something upstream of the injectors is telling the PCM a false fuel mix, that it is only injecting half the fuel it really is. Then when the downstream sensor reports the correct fuel/O2 mix, the math doesn't work out and it issues an error. I have new O2 sensors that I will put on when the driver side cat gets here.
All of my research to this point is that either the Mass Air Flow sensor is bad or the O2 sensor is bad. I have already replaced MAF. I was trying not to drive it until I get this worked out, but my son's car had to go to the shop, so I let him drive the Jeep for a few days. Then it started surging at idle and threw a P0300, multiple misfire code.
Does anyone have any thoughts? I feel like the tune I put back on it may have been corrupted, causing bad calculations. That is the only thing I can think of. Any assistance will be appreciated. The new cat will arrive between Wed and Friday. So it and the O2 sensors will be replaced by the weekend.
I am now getting false Rich Fuel codes for both banks. I say false, because the fuel economy it is reporting is double the actual mpg. Example, it is reporting 26 mpg when it is really only in the 13 to 14 range.
My hypothesis is that something upstream of the injectors is telling the PCM a false fuel mix, that it is only injecting half the fuel it really is. Then when the downstream sensor reports the correct fuel/O2 mix, the math doesn't work out and it issues an error. I have new O2 sensors that I will put on when the driver side cat gets here.
All of my research to this point is that either the Mass Air Flow sensor is bad or the O2 sensor is bad. I have already replaced MAF. I was trying not to drive it until I get this worked out, but my son's car had to go to the shop, so I let him drive the Jeep for a few days. Then it started surging at idle and threw a P0300, multiple misfire code.
Does anyone have any thoughts? I feel like the tune I put back on it may have been corrupted, causing bad calculations. That is the only thing I can think of. Any assistance will be appreciated. The new cat will arrive between Wed and Friday. So it and the O2 sensors will be replaced by the weekend.
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