P0171 code

Basically this means that an oxygen sensor in bank has detected a lean condition (too much oxygen in the exhaust). This code is triggered by the first downstream (front) Osensor. Refer to our Oxygen Sensor Code Diagnosis article for a list of all possible causes. Johnny is a longtime online writer and car enthusiast who has expertise in fixing car problems.

How to fix intake manifold gasket leak. Here is a discussion of their meaning and their. When the code says that the Fuel System is too lean, it means that the computer has been adding more and more fuel, which is called Long Term Fuel Trim. So, it is adding fuel to try and correct it. There are many things that can.

If there are no intake leaks, the next step is to replace the air filter and clean the air flow meter. They are logged together, since in Vand V(and more rarely in some 4-cylinder and straight 6-cylinder cars) the cylinders are split into two separate groups, or banks. Both of these codes reference a number that is given to you when you plug your truck into a OBDII scanner. If the problem persists the front oxygen (O2) sensor may need to be replaced.

A lean condition occurs when the engine either. The engine uses what are called Oor oxygen sensors in the exhaust stream to determine. This is one of the most common trouble codes in V-and larger engines.

It is either due to fuel being too little or air being too much. These problems are usually caused by a faulty MAF (Mass Air Flow) sensor. Editor’s Note: I highly recommend purchasing a bottle of MAF cleaner as your first step. But don’t take my word for it. L equipped car, pick up, van or SUV.

Let’s dive into this code. Causes, Symptoms, Severity and Cost. Generally, a lean code will cause the engine to run poorly, which the driver will notice as a high idle, a misfire, a lack of power, or even engine stalling, and this may happen before the check engine light has turned on.

First is a brief overview of this code. Bank is simply the other bank. Presumably, the MAF sensor is the culprit, so cleaning it should do the job.

However, if the cleanup still fails to fix the code, it’s best to inspect the oxygen sensors as well. Secondly, we check items like the Fuel Pressure and intake (any) gasket. These will let us know if there are any extenuating items that need addressing. In the case of vacuum leaks, you can spray some brake clean or carb cleaner around areas suspected of air vacuum leaks.

Now includes pictorial instructions on exchanging the transmission fluid in a 4R70W automatic transmission. Learn more about the error and how to fix it here. For Lincoln and Mercury cars and trucks: Air or vacuum leak, Oxygen Sensor or Mass Air Flow Sensor. Chevy or any GM vehicles: Air or vacuum leak or Mass Air Flow. The lean condition could be one of several possible causes.

The intake gasket could be leaking, in which case, the intake has to be remove and the gaskets replaced. One of the biggest misconceptions, about these two diagnostic trouble codes, is that they accuse the oxygen sensors as being BAD.

That varies by make and engine style, so make sure you check the shop manual. Auto Service Costs Find the prices for normal auto service activities including alignment, tuneup, timing belt replacement and more.

So I cleaned the maf sensor and continued to check it out. I found the hose clamp on the air duct hose that connects the ic to the tb was really loose and the back worked its self off a little. Fixed that and cleared out the code with the ap. It is often caused by intake air leaks, faulty fuel injectors and exhaust gas leaks.

Engine light came on a couple days ago. I took it to auto store to put on computer. MAF (mass air flow sensor)located on the air box Reset your CEL by unplugging the battery just turn the headlight switch on for seconds and that will clear it.

It is the case, however, that the system does work by vacuum lines - the vapors are fed into the intake that way. Depending on the year (which you didn’t mention) you might just be seeing two different problems from the same kind of course - really ol dried up vacuum tubing. So you should chech it on our car models.

Are you by chance running a MAFia an if so, when you returned to the stock tune, did you disconnect the MAFia? Can old downstream Oxygen sensor trigger that code , and should I also renew it? I had the code read again after light started staying on all the.

Unless the car has been fitted with an oiled air filter the MAF is not likely to be the problem and should be the last thing considered.

Those are the areas to check first. Hey guys, I figured I would go at this a second time with a little more educated a post. The code fired after I had taken the truck out in the desert for some fun for the first time. My has thrown that code twice, both times it took about minutes to locate the split vacuum hose under the hood.

Once was a funky hose that required a trip to an Audi parts counter, one was a typical vacuum hose I got from my local parts place.