The po170 fuel trim indicator came on. I wanted to know how to fix it I have 2 codes p0170 and p1188 I replaced the o2 sensor and cleared the other 2 codes. I need to know exactly what to do to clear these codes. I have a 1997 bmw 528i that won't pass emmisions and my tags are past due.

P0170 Fuel Trim Malfunction (Bank 1) OBD-II Trouble Code Technical Description Article by Dale Toalston ASE Certified Technician Fuel Trim Malfunction (Bank 1) What does that mean? This code is one that surfaces with certain makes of automobiles more than others. In writing this article I've added Mercedes-Benz-specific info since it seems that M-B (and VW) are most prone to having this P0170 surface along with misfire codes or other fuel trim codes. P0170 means there was a malfunction in the computer's control of the air:fuel ratio. It also indicates that the fuel trims reached their limit of adding fuel while trying to compensate for a actual or perceived rich condition. When the fuel trims reach their rich correction limit, the PCM (Powertrain Control Module) sets a P0170, indicating a problem or malfunction in the fuel trims. It may also have a P0173 referring to the same malfunction but on bank two. Symptoms Symptoms of a P0170 DTC may include: MIL (Malfunction Indicator Lamp) Illumination Start and stall Poor fuel economy Black smoke at tailpipe Hesitation/misfire at idle or under load Causes Potential causes include a vacuum leak, unmetered air leaks Fuel saturated engine oil Leak in turbo air charge hoses (if equipped) Possibly bad O2 sensor (If Mercedes, may require adaptation with M-Benz compatible scan tool.) Oil contamination in MAF connector or O2 sensor connectors. Also check ignition coils, cam and crank sensors, and oil sensor for leakage contributing to oil intrusion in wiring harness. Defective MAF (Mass Air Flow) sensor (especially on Mercedez-Benz and other European autos. There are a lot of problems with aftermarket MAF sensors.) Defective fuel pressure regulator Leaking camshaft adjuster solenoids (Mercedes-Benz). NOTE: for some Mercedes-Benz models there is a service recall for a crankcase vent hose located under the intake manifold. It should be checked for leaks/cracking and also operation of check valve in the hose. The check valve should flow only one way. Possible Solutions It should be stated right off the bat that the most common problem associated with this code is the MAF sensor or air mass meter. This is especially the case with Mercedes-Benz and Volkswagen and other European cars. At time of writing, you don't normally see this code with American-made cars, and minimally with Asian, and, to be honest, I have no idea why. It appears to me that the PCM (powertrain control module) logic used by some European car manufacturers to set a P0170 (or P0173) fault code simply isn't used by American vehicle manufacturers. It is more common to see P0171, 0174, 0172, 0175 codes set with regard to fuel trim malfunctions on American cars. There is very little information on the setting conditions for a P0170, or P0173, but what information that is available almost seems to be a redundancy of the P0171,4,2 & 5 setting conditions. I'm sure there's a reason for it, but I can't get anyone to tell me what that is. The similarities between them may be why we don't see this code surface on domestic vehicles very often. It's simply unnecessary. So, simply put, if you have a P0170, your PCM noticed that the fuel trims reached their rich correction limit. Basically it's adding fuel to try to compensate for a lean condition, real or perceived. If you have this code and access to a scan tool, observe the MAF sensor reading in grams/sec. The reading will be different for different automobiles, so get a good spec. I'm going to stick with what would be normal for a Mercedes (1.8L), since they have the bulk of the trouble. Expect to see at idle 3.5-5 g/s (ideally). At 2500 RPMs with no load it should be between 9 and 12 g/s. On road test, at WOT (wide open throttle) it should be 90 g/s or well above. If it's not in specs, replace it. Be careful of Ebay MAFs. Often they don't work according to OE specifications. If the MAF checks out and there is no oil intrusion at the connector, check fuel pressure and ensure that there are no leaks at the regulator internally or externally. Check all vacuum hoses and confirm none are cracked, disconnected or missing. Make sure there are no vacuum leaks at the intake manifold gaskets or tears in the air supply hose. If the engine is turbo charged, be sure the hoses are in good condition and have no leaks. Leaking turbo pressure hoses could cause a rich condition. Inspect the condition of crankcase vent hose under intake manifold and operation of check valve in the hose. (In the "What are the causes?" section) If there doesn't appear to be any problems with the fuel pressure, MAF or vacuum hoses, then inspect the O2 sensor connectors for oil intrusion. A bad O2 sensor could cause a P0170, or P0173. Repair cause of oil leak and replace oil-fouled O2 sensor.

Read more at: http://www.obd-codes.com/p0170
Copyright © OBD-Codes.com

P0170 Fuel Trim Malfunction (Bank 1) OBD-II Trouble Code Technical Description Article by Dale Toalston ASE Certified Technician Fuel Trim Malfunction (Bank 1) What does that mean? This code is one that surfaces with certain makes of automobiles more than others. In writing this article I've added Mercedes-Benz-specific info since it seems that M-B (and VW) are most prone to having this P0170 surface along with misfire codes or other fuel trim codes. P0170 means there was a malfunction in the computer's control of the air:fuel ratio. It also indicates that the fuel trims reached their limit of adding fuel while trying to compensate for a actual or perceived rich condition. When the fuel trims reach their rich correction limit, the PCM (Powertrain Control Module) sets a P0170, indicating a problem or malfunction in the fuel trims. It may also have a P0173 referring to the same malfunction but on bank two. Symptoms Symptoms of a P0170 DTC may include: MIL (Malfunction Indicator Lamp) Illumination Start and stall Poor fuel economy Black smoke at tailpipe Hesitation/misfire at idle or under load Causes Potential causes include a vacuum leak, unmetered air leaks Fuel saturated engine oil Leak in turbo air charge hoses (if equipped) Possibly bad O2 sensor (If Mercedes, may require adaptation with M-Benz compatible scan tool.) Oil contamination in MAF connector or O2 sensor connectors. Also check ignition coils, cam and crank sensors, and oil sensor for leakage contributing to oil intrusion in wiring harness. Defective MAF (Mass Air Flow) sensor (especially on Mercedez-Benz and other European autos. There are a lot of problems with aftermarket MAF sensors.) Defective fuel pressure regulator Leaking camshaft adjuster solenoids (Mercedes-Benz). NOTE: for some Mercedes-Benz models there is a service recall for a crankcase vent hose located under the intake manifold. It should be checked for leaks/cracking and also operation of check valve in the hose. The check valve should flow only one way. Possible Solutions It should be stated right off the bat that the most common problem associated with this code is the MAF sensor or air mass meter. This is especially the case with Mercedes-Benz and Volkswagen and other European cars. At time of writing, you don't normally see this code with American-made cars, and minimally with Asian, and, to be honest, I have no idea why. It appears to me that the PCM (powertrain control module) logic used by some European car manufacturers to set a P0170 (or P0173) fault code simply isn't used by American vehicle manufacturers. It is more common to see P0171, 0174, 0172, 0175 codes set with regard to fuel trim malfunctions on American cars. There is very little information on the setting conditions for a P0170, or P0173, but what information that is available almost seems to be a redundancy of the P0171,4,2 & 5 setting conditions. I'm sure there's a reason for it, but I can't get anyone to tell me what that is. The similarities between them may be why we don't see this code surface on domestic vehicles very often. It's simply unnecessary. So, simply put, if you have a P0170, your PCM noticed that the fuel trims reached their rich correction limit. Basically it's adding fuel to try to compensate for a lean condition, real or perceived. If you have this code and access to a scan tool, observe the MAF sensor reading in grams/sec. The reading will be different for different automobiles, so get a good spec. I'm going to stick with what would be normal for a Mercedes (1.8L), since they have the bulk of the trouble. Expect to see at idle 3.5-5 g/s (ideally). At 2500 RPMs with no load it should be between 9 and 12 g/s. On road test, at WOT (wide open throttle) it should be 90 g/s or well above. If it's not in specs, replace it. Be careful of Ebay MAFs. Often they don't work according to OE specifications. If the MAF checks out and there is no oil intrusion at the connector, check fuel pressure and ensure that there are no leaks at the regulator internally or externally. Check all vacuum hoses and confirm none are cracked, disconnected or missing. Make sure there are no vacuum leaks at the intake manifold gaskets or tears in the air supply hose. If the engine is turbo charged, be sure the hoses are in good condition and have no leaks. Leaking turbo pressure hoses could cause a rich condition. Inspect the condition of crankcase vent hose under intake manifold and operation of check valve in the hose. (In the "What are the causes?" section) If there doesn't appear to be any problems with the fuel pressure, MAF or vacuum hoses, then inspect the O2 sensor connectors for oil intrusion. A bad O2 sensor could cause a P0170, or P0173. Repair cause of oil leak and replace oil-fouled O2 sensor.

Read more at: http://www.obd-codes.com/p0170
Copyright © OBD-Codes.com

PO170 Fuel Trim Malfunction (Bank 1)

I'm going to guess you do No Preventative
Maintenance what so ever, or know what is needed

The Oxygen Sensors get replaced at 100,000 miles
or when they fail or when their switching times & data
are not as it should be

Spark Plugs-every 3 years

It costs money to work on a vehicle to learn how things are
& collect needed data, when it appears to get you places
with no issues,then you have problems & lots of them & no
record of when it did work correctly

O2 Sensors are big part of fuel trim-- IF-- you have no vacuum
leaks or cylinder misifres

An old blocked exhaust converter can be a problem

I would:
Replace the spark plugs
Replace all O2 Sensors
Clean the MAF Sensor
Replace any cat over 12 years
Check Fuel Trim
Check to see all 8 Emission Monitors run-- on a long 25
mile road test-after other work is caught up
EGR -issues
Exhaust Leaks before converter
Evap System-Leaks

Have to check & test it all-the entire vehicle
BEFORE -you replace the cat

Fault code P0170 fuel trim malfunction (Bank 1) for Hyundai Tucson 2008

P2626 O2 Sensor Pumping Current Trim Circuit/Open
P0171 System too Lean (Bank 1)
P0170 Fuel Trim Malfunction - Bank 1.

Try changing the fuel filter first. Then you will have to clear the code with a jumper.

Check here:
http://www.troublecodes.net/Kia/

P0304 = #4 cylinder misfires
P0170 = Fuel Trim, Bank-1
P0173 = Fuel Trim, Bank-2
P1250 = this is invalid code for BMW
P1188 = Fuel control, bank-1, sensor-1 (pre-cat sensor)
P1189 = Fuel control, bank-2, sensor-1 (pre-cat sensor)
Vacuum leaks and/or sensor defective for the issues of the codes.
This error codes really need parts to replace. But you have to replace the thermostat first. Then clear the codes and see if any reappears,then replace defective part/s

P0170....Fuel Trim (Bank 1)

from reading the code it is about fuel and its the mixture isnt correct ,this i think is being caused by a faulty O2 sensor on bank one but as iam in europe and out gallants are normally a 4 cyl engine i am afraid i couldnt tell you whats bank one weither its the left side or the right side but if you can find out what side is bank one then its just a case of testing the O2 sensor with a automotive meter then changing the appropiate sensor as theri are two sensors fitted one before the cat and one after but without a tester on it its difficult to say but i would check the after the cat sensor first.

These codes will have to be cleared and the car driven through a drive cycle, maybe a couple of times, is the check engine light off? Also you should check your MAF sensor it may need to be cleaned or replaced and makes sure there are no holes in your intake tubing. Hope this helps, let me know.

p1188: Fuel Control (Bank 1 Sensor 1)
p1189: Fuel Control (Bank 2 Sensor 1)
p0171 and p0173: These are very common codes on BMW's which can also be false codes, try clearing the codes and run the test again they may not come up again.
p1250: Never came across that....

SAE Code P1188 DTC Code 17596 Description Linear 02 Sensor / Compensator Resistor Short to ground SAE Code P1189 DTC Code 17597 Description Linear 02 Sensor / Compensator Resistor Short to B+ SAE Code P0170 DTC Code 16554 Description Fuel Trim, Bank1 Malfunction

Basically you need a new oxygen sensor, The fuel trim code is from the computer trying to adjust the fuel/Air mixture to compensate for the bad signal from the sensor. Just change the one closer to the engine, the one behind the Catalytic converter will thow a different code when it fails.