On this particular engine, it is the intake manifold gasket that goes bad and leaks engine vacuum resulting in this code. There probably is a malfuction in the match up between the computer and the sensor feedback loop that is preventing the air and fuel ratio to be mixed properly. A mass air flow sensor can be tested with a scan tool; read more here:. I do notice that just before the light comes on that there is a slight hesitation, split second, in the power. The best place to take your car for diagnostics is your local dealer - their technicians are factory-trained and know the common problems with the cars they service. Based on my experience, this condition can be and usually is but not always associated with a performance or rough running condition.
The last time my light was on it was because of the gas cap so I just pulled the fuse and reset the light. Does the intake boot have any cracks? Based on my experience, if this was the case, it will also flag large and small Evaporative Emission codes. Look for kinks, cracks, etc. Coincindentaly, this happended about two days after I got it back from the dealership to have a brand new transmission and clutch installed, so I'm wondering if something in the exhaust system is not put back together correctly. Ford has issued a technical service bulletin on this issue.
Could I have a bad fuel injector? I would think that better mileage would mean better emission. The grams per second at idle should be about 1. If the fuel trims go up or start to climb positive, this indicates a leaking brake booster. If anybody has any ideas please let me know. Instead I went home and looked at the sensor myself. It may or may not be associated with the P0171 lean code. Unfortunately this didn't fix the check engine light.
An air leak anywhere between the engine intake and the mass air flow sensor is often called a 'vacuum leak' or 'intake leak'. So it it has a vacuum leak, it will show up at idle or lower engine rpms and usually cause a surging or high idle condition if the vacuum leak is large enough. Good fuel trim numbers are 0% or as close to 0% as possible. The Smog check failed becasue of this. I'm not ready to give in just yet. I am also noticing poor gas mileage.
I think it might have been clogged up or something. Note: This is the same 2. Drive for a month then the light comes back on. Please be sure to reference a year and model-specific repair manual or speak with a qualified professional automotive technician before completing a repair to your vehicle. So far it hasn't come back. Bruce had similar problem and says this: I know this is late, but I got the same code recently.
Again, a dirty air filter can and will eventually cause the mass air flow sensor to get contaminated and go bad. Much appreciated was that he got the parts to be covered by Toyota and I just had to pay for the labor only. She only drives in the city too. This will not affect the way the engine accelerates. For example, the engine will bog down or hesitate while accelerating or it will stall or surge at lower engine rpms. Without a scan tool, the only way to find the problem is to check the basics and research common problems with your particular car make, year and model. However, I have not found that this is related to or that it has caused any of these codes above.
I take it into get smogged and it fails. Anyway this code comes up once and awhile when the connection gets flaky. 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. To lookup your particular code, visit our. However, it is important to note, that this sensor should only be changed after replacing the mass air flow sensor or ruling it out as a possible cause and fixing any air or vacuum leaks under the hood first. You often find P0420 and 0430 together and basically it means that the catalytic converter isn't performing as it should.
It was funny that the car's O2 readings didn't fluctuate while accelerating or decelerating when we did the test. This very well could be caused by the code P0174 System Too Lean Bank 2. Or, does this mean If I drive more it can be recovered? When this problem first occured I was under 100k but am now at 104k. Sensor reacts normal to spike and active tests. Toyota probably does not want to admit it.