All lean codes WTF!!
12-25-2010, 08:30 AM
#11
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Join Date: Aug 2006
Location: Central NJ
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After clearing the codes about 4 times and retuning I started throwing 0174 1130 1150. Since it's showing lean in bank two and just excessive fuel in both banks I'm gunna try to replace the drivers o2 sensor and hopefully that's the problem
12-25-2010, 09:13 AM
#12
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
Have you checked the fuel pressure yet?
The P1130 and P1150 codes are reporting that the short term fuel trims on both banks are maxed out--either rich or lean, these codes do not make that distinction. They are just saying that one or the other limit has been reached.
However, P0174 is reporting lean on bank 2, so now we know that a lean condition is what trigged P1130 and '50. As the bank 2 fuel rail is at the end of the line, it will often report lean before bank 1 (but we know both banks are having issues as both DTC P1130 and '50 were thrown).
Now look at the possible causes for P0174 (same potential causes as P0171). You will see that the O2 sensor is not on the list--in fact it is most likely that the sensor is good and doing its job by reporting the lean condition.
The possible causes for P0174 do include, quite prominently, low fuel pressure:
Fuel System
So what these codes are telling us is that the PCM is doing it's best to correct a lean condition, but it has reached the limit of it's ability to do so; most likely because there is insufficient fuel being delivered to meed the need.
I.e. check the fuel pressure before you spend money on a new O2 sensor...
The P1130 and P1150 codes do indicate the O2 sensors as possible causes--but also excessive (or insufficient) fuel pressure--again, check that first before replacing what might be perfectly good
The P1130 and P1150 codes are reporting that the short term fuel trims on both banks are maxed out--either rich or lean, these codes do not make that distinction. They are just saying that one or the other limit has been reached.
However, P0174 is reporting lean on bank 2, so now we know that a lean condition is what trigged P1130 and '50. As the bank 2 fuel rail is at the end of the line, it will often report lean before bank 1 (but we know both banks are having issues as both DTC P1130 and '50 were thrown).
Now look at the possible causes for P0174 (same potential causes as P0171). You will see that the O2 sensor is not on the list--in fact it is most likely that the sensor is good and doing its job by reporting the lean condition.
The possible causes for P0174 do include, quite prominently, low fuel pressure:
Fuel System
- Fuel pressure regulator (leaking, malfunctioning, etc.).
- Fuel filter plugged, dirty.
- Fuel pump (weak, check valve leaking, etc.).
- Leaking/contaminated fuel injectors.
- Low fuel pressure or running out of fuel.
- EVAP canister purge valve leaking (when canister is "clean").
- Fuel supply line restricted.
- Fuel rail pressure sensor (incorrect reading).
So what these codes are telling us is that the PCM is doing it's best to correct a lean condition, but it has reached the limit of it's ability to do so; most likely because there is insufficient fuel being delivered to meed the need.
I.e. check the fuel pressure before you spend money on a new O2 sensor...
The P1130 and P1150 codes do indicate the O2 sensors as possible causes--but also excessive (or insufficient) fuel pressure--again, check that first before replacing what might be perfectly good
12-25-2010, 09:21 AM
#13
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Ok I will get on that either tomorrow or Monday since I am stuck working on Christmas from 8am to midnight.what is the proper pressure and how do I check it? Thanks cliffy you always have the best info even on Christmas! Merry Christmas
12-25-2010, 09:27 AM
#14
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I did get a fuel pressure reg malfunction code a month ago cleared it and it never came back. I heard a 2 step can damage these since they're electronic and the xcal 2 step cuts fuel to work and I started using this around the same time these codes started.
12-25-2010, 10:07 AM
#15
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
If you are lucky there will be a Schrader valve at the front of the passenger side fuel rail (I think the '02s have them, my late production '03 does not) which will allow an adapter and gauge to be attached. If not you need to break the fuel line connectors just before the passenger side rail and install an adapter.
If you have the Schrader valve Actron has a kit that's usually $30 to $40 at your FLAPS.
Measuring the actual pressure in this manner it should be 39psi minus the manifold vacuum in psi¹. At idle the vacuum is 18 to 22 inHg, or 8.8 to 10.8 psi, so the fuel pressure should be 19 to 31 psi.
It can also be checked with a data logging scan tool, however this will only report what the PCM thinks the f/p is, a bad pressure sensor might be lying to the computer so it's best to check the actual pressure. When observing this PID (010A) the pressure should be 40-43 psi at hot idle.
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¹ - The PCM maintains the fuel pressure so that the pressure drop across the injectors is always 39-40 psi. This is why there's a manifold vacuum connection to the fuel rail pressure sensor.
If you have the Schrader valve Actron has a kit that's usually $30 to $40 at your FLAPS.
Measuring the actual pressure in this manner it should be 39psi minus the manifold vacuum in psi¹. At idle the vacuum is 18 to 22 inHg, or 8.8 to 10.8 psi, so the fuel pressure should be 19 to 31 psi.
It can also be checked with a data logging scan tool, however this will only report what the PCM thinks the f/p is, a bad pressure sensor might be lying to the computer so it's best to check the actual pressure. When observing this PID (010A) the pressure should be 40-43 psi at hot idle.
------------------------------------------
¹ - The PCM maintains the fuel pressure so that the pressure drop across the injectors is always 39-40 psi. This is why there's a manifold vacuum connection to the fuel rail pressure sensor.
12-25-2010, 10:24 AM
#16
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Location: Central NJ
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Ok thanks. I'm going to check the pressure at the valve (which I have) and check my vacuum psi and I'll datalog with my xcal. If datalogginh shows correct pressure but gauge does not I guess it's the reg
12-25-2010, 01:53 PM
#17
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Location: Whitehall, Michigan
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If you're boosted it's actually really common for those regulators to go bad. They aren't designed to handle boost.
12-28-2010, 02:11 PM
#19
1st Gear Member
Join Date: Dec 2009
Location: OK
Posts: 83
I'm having the same 1131 and 1151 codes thrown for a long time now. i cannot seem to find the problem either. i take it your 1131 and 1151 codes have gone away now since your PCV catch can? I have an EGR delete also. In other threads i've talked about a hissing sound only at mid load, does yours do this ever? An exhaust leak is hopefully what could be causing part of this.