Codes P0301, P0300, P0302 and P0304, misfire, fuel issue, start then bog down, stopped running

Hi,

The fuel mixture seems lean based on the codes. I realize you replaced the fuel pump. Is the pressure within the manufacturer's specifications? Have you checked for engine vacuum leaks?

Here is what I suggest. First, confirm there isn't an issue related to a faulty crankshaft position sensor. If it checks good, take your scanner and check the short-term fuel trims. Once you do that, let me know the results. That will tell us if it is running rich. Since you replaced the sensors and it's running better, it should provide a good reading.

One other thought. By chance have you checked to see if the catalytic converter is plugged? If you remove the O2 sensor (pre cat) will it run any better?

Let me know.

Joe

Hi,

That will do it. By law, you aren't to remove the insides. Will it run okay? Well, it certainly will run much better. The issue is the O2 sensors will not get accurate readings and cause the check engine light to turn on, and I don't know where you are located, but it will likely fail an emissions inspection.

Let me know if you have other questions.

Take care,

Joe

Hi,

Like anything else, the converter simply wears out. Considering internally, they run at about 1500 degrees F, constant pressure from the exhaust, bumps, hitting things, and so on, they come apart.

The vehicle has two converters. One is integral with the exhaust manifold (pic 1) and the other is under the vehicle (pic 2). If nothing got into the second one, it should be okay.

As far as it being legal, the federal government has implemented laws to lower exhaust emissions. The vehicle is designed to meet a specific standard. Removal is not permitted by law. However, you asked if it comes apart without you knowing. The only way to know it is by checking the engine light, changes in performance, and so on.

Being it is a federal law; I have to tell you it is illegal to remove it. I hope you understand.

We don't offer a face time option. However, that really isn't a bad idea at all. I will suggest it to the site owner.

Regardless, let me know how it runs once you get it back together. Also, if you have questions or if I can help in any way, let me know.

Take care of yourself,

Joe

See pics below.

The Po420 is an indicator of the issue with the catalytic converter. Interestingly, there are no short-term fuel trims showing up. That is likely related to the oxygen sensor (B1 S1). The code indicates there is no ground signal to the sensor.

If you look below, I provided the directions related to testing the circuit. This could be throwing things out of wack simply because the fuel mixture is off.

Let me know.

Joe

Hi,

I need to better understand something. How was the converter cleaned? Also, was the front converter the one that was damaged?

Let me know.

Joe

Hi,

I never heard of anyone doing that. Anyway, the pic above shows two connectors. One is in the vehicle (C183) at the PCM (see pic 1) and at the O2 sensor (C166). Take a look at the pics below and let me know if that is where you were looking.

Take care,

Joe

Hi,

You are correct. Pic 2 shows the O2 sensor at the front of the engine. As far as resistance issues, most times it is related to a corroded connector or simply a weak connection. If you find the resistance is high, what I do first is simply clean the connectors, inspect them to make sure nothing was damaged or pushed in, and then I put dielectric grease in the connector first. Usually, that takes care of the issue.

Let me know what you find.

Joe

You have an open circuit in that wire. It's likely broken at some point. If you checked it with both ends disconnected (Sensor and PCM) and got 0, it's open.

Are you able to trace that wire to inspect it? Are you getting a signal ground at the PCM itself?

Let me know.

Joe

Hi,

If you are checking at the PCM, you should receive a ground signal when the key is on at the PCM pin which is open. A signal ground is used as the reference point for internal electronics. In this case, the PCM.

I hope that makes sense. LOL.

Let me know.

Joe