In the second photo, you can see a chunk of a leaf that blocks the sensor wire. The signal circuit monitors changes in voltage on the variable resistor as the pintle moves. Symptoms: The engine computer uses the mass air flow sensor signal to determine how much fuel to inject. Since exhaust gas is inert, it displaces oxygen and fuel, thereby lowering cylinder temps, which, in turn, lowers oxides of nitrogen emissions. Usually they make a knocking noise when bad. As it's open more, the voltage should increase accordingly.
The other is the Oxygen senor. If it is damaged, repairing it should solve the problem. A dirty throttle body will need to be cleaned and the intake will have to be tested for vacuum leaks. When the condiyion is fixed, will the computer reset, or will I need to go back to Autozone to clear the codes? If the light continues to illuminate, then you will know that the will need to be replaced. When I get the chance I think I'll give cleaning a try and give the connectors and wiring another look. How do I troubleshoot code P0404 on a 2001 1500 Z71? I was wondering if anyone had any luck cleaning these and what the odds are that the code may be caused by another problem or sensor out of tolerance.
Will get back on it later this weekend. One of the symptoms of a leaking intake gasket is the engine running rough when started cold. Many thanks for your help. Thanks, I just saw the other post concerning P0404. The amount of air entering the boot through this crack is not measured by the sensor, therefore the airflow sensor reads a much lower amount of air flow than actually is. Truck has 178000 miles on it.
This problem is common in many European vehicles, e. Earning a living as an electronics technician in another field, I've learned the hard way that error codes can be both useful and misleading. Check the throttle body and clean it if it's dirty. To diagnose this issue, exhaust back pressure or the engine vacuum must be checked. A leaking purge valve, as well as brake vacuum booster can also cause this problem. This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation.
One of the symptoms of a vacuum leak is the hissing noise from under the hood when the engine is idling. Examples of what can cause the code P0101 Often the code P0101 is caused by a vacuum leaks. Check for a good 5 Volt reference voltage to the connector. Tab will move on to the next part of the site rather than go through menu items. It must be checked and cleaned.
I think ther is a gm bulletin on this. Accompanied symptoms may include misfiring codes P0300 to P0308, lack of power under heavy load or on acceleration, overheating of the catalytic converter and poor gas mileage. When doing these repairs, either way, you will want to make sure all of the electrical connections are clean, dry, and tight. I've already received a high dollar ticket for expired inspection, but this is my work truck, so can't avoid driving it. Since exhaust gas is inert, it displaces oxygen and fuel, thereby lowering cylinder temps, which, in turn, lowers oxides of nitrogen emissions.
Dec 22, 2013 P0405 means Exhaust Gas Recirculation Sensor A Circuit Low. I realize that I am combining two issues in one query. Other possible sources of vacuum leaks must be inspected. There are pros and cons to both repairs that you are considering. It should indicate a good ground.
Please feel free to leave a comment below if there is anything that you would like to add that can improve this article. Posted on Nov 11, 2009 Thanks for your response!! Detonation can lead to engine damage. Now I am working on P0135, the oxygen sensor s the code reader at Autozone said the O2 on abnk one was the cause of the P0135. Checked all the hoses that I could get to. If this is not the problem the it gets a little more complex from here. See the photo of a clogged up mass airflow sensor below.
The valve controls exhaust flow going into the intake manifold from the exhaust manifold through an orifice with a controll module controlled pintle valve. Thank you for writing in. Many thanks for your help. What repairs can fix the P0404 code? The site navigation utilizes arrow, enter, escape, and space bar key commands. Any words of wisdom, experience, and opinion welcome. Found a great service manual on www. Up and Down arrows will open main level menus and toggle through sub tier links.