Car running rich as @^$%, intermitantly
Thread Starter
Staging Lane
Joined: Jan 2005
Posts: 93
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From: Columbia S.C.
Car running rich as @^$%, intermitantly I've got a bald spot from scratching my head on this one. At times, seems mostly on a hot start, car will run very rich on bank 1 only. Fuel trims will be between 25% and 50%, both long and short term. Sensor 1 looks fine and is switching good, but sensor 2 will be steady around 950mV. Never had a problem on bank 2, but that banks sensor 2 also is steady around 750mV. Bank 1 CAT is only about a year old, as is B1S2 O2. both OEM items. All other O2's are only months old, and are Bosch items. I have not found any vacume or exhaust leaks. Car is stock internaly, with stock PCM, exhaust manifols and CAT's. It has an SLP lid, K&N filter, and SLP LM exhaust. MAF is stock and has been recently cleaned, like 4 days ago. MAF is reporting around 6.1 grams a second, so I don't think it is over reporting the air flow. It has set a
P0138 code which is Bank1 Sensor 2 High Voltage. This is an intermitant problem that may not occur for a week and then my occur for several days in a row. When the problem does occur, you can most times get it to clear up by performing a quick WOT snap. Also, it seems that it has failed several Mode 6 tests. EVAP purge leak vacume fail test, idel catlyst efficency test on bank 1 and 2, and No EGR off idel test;MAF out of range high and low. My gut tells me the EVAP or AIR system is dumping air into the exhaust at the wrong time and making the PCM think the system is lean, and causing it to over correct. If I'm right, why is only bank 1 going crazy? Any suggestions on where to go from here? Thanks in advance for any help. Wife is driving me crazy to fix this as it's her car.
P0138 code which is Bank1 Sensor 2 High Voltage. This is an intermitant problem that may not occur for a week and then my occur for several days in a row. When the problem does occur, you can most times get it to clear up by performing a quick WOT snap. Also, it seems that it has failed several Mode 6 tests. EVAP purge leak vacume fail test, idel catlyst efficency test on bank 1 and 2, and No EGR off idel test;MAF out of range high and low. My gut tells me the EVAP or AIR system is dumping air into the exhaust at the wrong time and making the PCM think the system is lean, and causing it to over correct. If I'm right, why is only bank 1 going crazy? Any suggestions on where to go from here? Thanks in advance for any help. Wife is driving me crazy to fix this as it's her car.
