In technical language this adjustment is called fuel trim. I ended up buying the fuel pressure gauge kit on Amazon and tested the fuel pressure. Am I hurting the car in anyway by doing this? This could mean that the cat is shot, but hopefully, in this case, and given the previous symptoms - it's because the cat is being fed with a sub - optimum mixture as a result of incorrect airflow rate. Often this code could be caused by a vacuum leak e. It's good when the two codes come up together - it sort of cross confirms over both banks that the fuel mixture is weak to the extent that the Lambdas cannot correct. I did not cover the Toyota Tacoma or Tundra. If I'm getting both of these codes at the same time, could it mean I have some type of a vaccum leak? If the fuel pressure is lower than the specifications or if the fuel pressure leak down below 21 psi after the engine is turned off, the fuel pump has likely failed and will need to be replaced.
Drive for a month then the light comes back on. The mechanic decided to clean the throttle body and the light never came back on. Scanner Danner is the Jedi Master of auto diagnosis. I was advised to not drive it. If anybody has any ideas please let me know.
After putting it back in and resetting my check engine light, the car worked great! I'm not ready to give in just yet. Are any of the vacuum lines or hoses disconnected? The calculated load reading should increase to 85% or higher on a wide open throttle acceleration. Based on my experience, the mass air flow sensing element gets dirty because of a dirty air filter that has not been serviced or replaced regularly. Any vacuum line that looked shabby I replaced. An air leak anywhere between the engine intake and the mass air flow sensor is often called a 'vacuum leak' or 'intake leak'.
Further diagnostics may require measuring voltage at sensors, cylinder balance tests, live data tests with a scanner, possibly measuring resistance on wiring from ecm to o2. In 80% of cases it's due to a dirty filament on the airflow meter so that it under-reads the airflow and therefore sets too low a fuel flow. Until recently, the engine started having trouble when I first started it up. Inspect wiring as much as you can see. There was an amber colored plastic thing that was really dirty so I cleaned it. If there are no intake leaks, the next step is to replace the air filter and clean the air flow meter. They updated the intake manifold gasket: Above: updated intake manifold gasket You can differentiate the old gasket from the new by the color — the original gasket was black, the new is orange.
Connecting the two ports is a motor driven valve. For example, if over time, the engine gradually develops a small vacuum leak, it makes the engine run leaner more air and less fuel. The service manual at the dealership did not mention any such sensor. The funny thing is that with p0171 code, my Mileage went up from 23-24 Miles per Gallon to 25-26 Miles per Gallon. Might as well clean throttle bore and valve while you have it apart.
Technical tip: A leaking intake manifold gasket will cause this lean code to set during the warm up process in most cases. What was the final verdict?. Remember, this is only for bank 1, not bank 2. However, keep in mind, the theory and operation is still the same when it comes to a lean condition on the V8 engine and all other internal combustion engines with this similar Toyota fuel system. It was 100% due to the gas I got that day.
This was awesome because it was such an easy thing to do once I realized what I had to clean. Normal numbers at idle and high positive numbers under a load indicate a faulty mass air flow sensor. So far it hasn't come back. You can test the mass air flow sensor using a scanner or a voltmeter. Even if it did go bad, I have not seen it flag a lean code. Check the condition of the Air filter Replace if need. How the code P0171 is diagnosed: With a good scan tool that shows the live data diagnosing the code P0171 is fairly easy.
This might end up in the news at some point as a product recall due to defective design. The Engine Control Module calculates the necessary compensation to correct the offset between the actual and the theoretical ratios. I changed the bank 1 Catalytic Converter and o2 sensors because the codes read they were the problem. They are barely noticeable and the car seems to drive just fine. A mass air flow sensor can be tested with a scan tool; read more here:.
If the code P1130 return Replace the Air fuel ratio sensor. We drove around and recorded the voltages for the sensors -- 3. Time is running out on the inspection extension they gave me. The new and improved or updated part number for the intake manifold gasket is. . If the problem resolves once the car warms up you likely have this issue. As of today are you still having this issue??.
Pero segun tengo entendido el problema de Ecu solo es en 2001 a 2004,. I also have a 2002 Sequoia and swapping filter into that same engine was fine no errors. Air fuel ratio sensor has failed. If you have access to a scanner that can read live data, you may notice the fuel trims are high at idle and high while at steady cruise. Scanner Danner is the Jedi Master of auto diagnosis. A: The code P0300 means that multiple cylinders are misfiring. Open the hood, and locate the mass air flow sensor.