P0174
#1
12-16-2018, 05:46 PM
P0174
I have a 2000 f150 4.2. The check engine light came on recently so I scanned it and it shows code p0174(system too lean bank 2) and if I’m correct I beleive bank 2 is the driver side. The truck has also accumulated a fairly large exhaust leak on what sounds like the driver side recently and this code had not shown until after the leak got larger. It’s too the point where u can hear it clear as day and it is quite loud in the passenger compartment espessialy upon cold start or heavy exceleration. My question is if an exhaust leak can throw that code. Any help would be appreciated, trying to resolve this as soon as possible.
#3
12-16-2018, 07:32 PM
The ox sensor is located down the head pipe a short distance.
If the head pipe to header has a leak, it can actually draw air in as the exhaust gas passes by during pulses.
The sensor doing what it does, detects the extra oxygen and signals the computer to 'richen' the fuel to that bank.
This results in the code if either of two parameters are met. A leak in the intake tract or a leak in the exhaust as described.
The long term fuel table is shifted 25% or the program detects the tables are too far out of a normal difference range.
If you look at the long term fuel tables for both banks with a Scanner you can tell which condition caused the code to set, just for the knowledge gained, if interested.
You will have to fix the leak or the code will remain and continue to cause an increase in fuel consumption
After the repair, clear the code. The computer will go into full diagnostics and clear out any shift in both tables, then rebuild them to current conditions..
After several drive cycles, the code should not re appear and a check with a Scanner should show both tables are within less than 10% shifted indicating the operation is within accepted program limits..
Good luck.
If the head pipe to header has a leak, it can actually draw air in as the exhaust gas passes by during pulses.
The sensor doing what it does, detects the extra oxygen and signals the computer to 'richen' the fuel to that bank.
This results in the code if either of two parameters are met. A leak in the intake tract or a leak in the exhaust as described.
The long term fuel table is shifted 25% or the program detects the tables are too far out of a normal difference range.
If you look at the long term fuel tables for both banks with a Scanner you can tell which condition caused the code to set, just for the knowledge gained, if interested.
You will have to fix the leak or the code will remain and continue to cause an increase in fuel consumption
After the repair, clear the code. The computer will go into full diagnostics and clear out any shift in both tables, then rebuild them to current conditions..
After several drive cycles, the code should not re appear and a check with a Scanner should show both tables are within less than 10% shifted indicating the operation is within accepted program limits..
Good luck.
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