Check Engine Codes 0171, 0174, 0175
Thread Starter
Newbie
Joined: Jul 2007
Posts: 16
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From: Glencoe, Illinois
2002 C320 Sedan
Check Engine Codes 0171, 0174, 0175
Finally got around to hooking up an OBD reader and checking the codes (check engine light)on my '02 C320 today and those 3 error codes showed up. The OBD indicated they are for right bank lean, left bank lean and right bank rich. I reset the check engine light and drove about 80 miles home. Within a few miles of home, the ckeck engine light illuminated again. I am assuming it is related to one of these 3 fault codes. Anyone with some experience who can tell me a likely cause of the problem?
Car runs greats and has 55,200 miles.
Car runs greats and has 55,200 miles.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 6,211
Likes: 2
From: Laguna Niguel, CA
Haha, too rich, too lean, can't make it's mind. Disconnect your MAF sensor (should be just past the air filter but before the throttle bodies and is part of the intake tubing and has a wire/connector coming out of it). If the car still runs fine and you don't get these very same codes (you will get a MAF malfunction and that's OK) then it's the MAF. If you still get these codes after removing the MAF then it's a vacuum leak.
If it's the maf, remove the insert (may require security torx bits) and spray the gold tip hard and long with CRC MAF Sensor Cleaner ($6 at Pep Boys). Do not touch it with your finger, you will contaminate it. These codes are likely because the sensor is dirty and just needs cleaning. Alternatively you can take it to the dealer, figure $800 but you will get a loaner and complimentary car wash.
Also, just because you think your car is fine doesn't mean it's so. What happens with these codes is the sensors may think it's very lean and end up running the car too rich causing carbon deposits. Or, it thinks it's rich when it's not and ends running lean and may cause detonation. At best you will get worse fuel mileage, at worst you are damaging your engine. Either way, it's costing you more money not to deal with it than you think.
If it's the maf, remove the insert (may require security torx bits) and spray the gold tip hard and long with CRC MAF Sensor Cleaner ($6 at Pep Boys). Do not touch it with your finger, you will contaminate it. These codes are likely because the sensor is dirty and just needs cleaning. Alternatively you can take it to the dealer, figure $800 but you will get a loaner and complimentary car wash.
Also, just because you think your car is fine doesn't mean it's so. What happens with these codes is the sensors may think it's very lean and end up running the car too rich causing carbon deposits. Or, it thinks it's rich when it's not and ends running lean and may cause detonation. At best you will get worse fuel mileage, at worst you are damaging your engine. Either way, it's costing you more money not to deal with it than you think.
