Check engine light on

Additionally I used Lucus fuel Injector cleaner 3 times and also replaced gas cap.

Hi Carl, the short-term fuel trims normally should be between -10% and +10%. If the engine is under a heavy load and you are pressing hard on the throttle, it will increase above +10%. The higher gears will normally place more of a load on the engine, so that is a possibility.

So, can you tell me if there are drivability issues? Also, have you retrieved any diagnostic trouble codes indicating a problem?

Let me know as much as you can. I will watch for your reply.

Take care,

Joe

Thanks for answering my questions. DTC is P219A lean bank one. I believe that this is a generic code and opens up a lot of possibilities. Correct me if I am wrong, I believe that ltft 1 is at idle, ltft 2 is recorded from 0 to 15 mph , ltft 3 is from 15 to 30 mph and ltft 4 is from 30 to 50 mph.I ruled out a vacuum leak because the ltft went from 4% in 1 and 2 to maxed out at 33% in 3 and 4. The vehicle has a very slight rough idle when at a stoplight, however there are no issues when driving. No backfire no hesitation no stalling. If I go to WOT it takes off and hauls ass. My next attempts will be replacing the fuel filter and then checking out the fuel pump or fuel pressure regulator. I am guessing that the ECM is adding fuel to the engine after the vehicle reaches higher speeds.

Hi,

The fuel filter is a good idea. If it is restricting fuel delivery, it certainly can cause a lean mixture. As far as the regulator, here is a link that explains how to check the fuel pressure and the regulator:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Since the lean mixture is only bank 1, I have to ask. Are there any exhaust leaks? If you have one upstream, it can create a lean signal to be provided by the downstream sensor.

Let me know.

Joe

Hey Joe, I went to order a fuel filter but found out it is unserviceable because it is in the fuel tank. As for an exhaust leak, would that not be evident also in the long-term fuel trim at idle and the long-term fuel trim at 0 to 15. I'm showing a good number on long-term fuel trim one and two. Would not a leak vacuum or otherwise be evident in all four long-term fuel trim freeze frames.

Also, I can easily access the fuel pump while it is in the tank from the floorboard in the Avalanche as I have replaced that fuel pump 50,000 miles ago is there or should I look at inspect the fuel pump as it is now sitting in a fuel tank.

Hi,

A vacuum leak would cause a lean fuel mixture. Do you know what the short-term fuel trims are? Also, since it is only one side, make sure you don't hear a ticking sound from in front of the catalytic converter (manifold) which can cause a lean mixture.

I attached the description and possible causes below. Note: that one is an exhaust leak pre catalytic converter. That's why I'm suggesting it could be an issue.

Also, toward the end of the descriptions are directions specific to circuit testing. Take a look through them and let me know if you feel comfortable doing them.

Let me know.

Joe

See pics below.

So, to be clear I'm trying to understand the four freeze frames data that's recorded on my code reader. I have freeze frame number one that shows short-term fuel trim and long-term fuel trim at 4%. I have a second freeze frame that's showing short-term fuel trim and long-term fuel trim at 3%, which I believe represents 15 to 30 MPH, then I have another freeze frame number three and it has a short-term fuel trim and long-term fuel trim maxed out at 33% and then I have a fourth freeze frame that shows short-term fuel trim and long-term fuel trim maxed out at 33%. so, am I wrong in thinking that something is throwing that check engine light on when my vehicle is under load?

Hi,

No, sir. You are not wrong. Based on the info you provided, that is very possible. I may have already asked, but have you checked fuel pressure, for vacuum leaks, and the engine coolant temperature sensor signal? Also, are there any exhaust leaks?

Let me know.

Joe

Morning Joe, I used another code reader and ran more data off my diagnostic port found my fuel rail pressure to be at 315KPAG which I then found means 45 psi to my fuel rail IM guessing that’s low might that be causing my problem.

I forgot to include that that rail pressure was off my freeze frame which occurred while I was under heavy load.

Just want to do include one other thing that this new code reader gave me an absolute load value at the time of the freeze frame at 49% and my speed was 60 miles an hour.

Hi,

I believe fuel pressure should be between 55 and 60psi at idle. However, if it is a flex-fuel vehicle, 45 is likely correct.

Let me know.

Joe

Thanks again Joe, l have been using another code reader and cleared the code yesterday. Today the Check Engine Light came on and I used the new code reader. Now in addition to the P219A I also have a P2200, and it says that this code has set the Check Engine Light. I have replaced the two upstream O2 sensors and the code reappeared P2200. Since I have the P219A should I be looking at number 1 bank only?

Interestingly, the P2200 isn't listed on this year and model. See pic 1.

The code itself indicates that NOx gases readings are out of parameters. In most cases, the code is set due to a faulty catalytic converter. However, that usually happened due to a different problem such as a misfire, rich fuel mixture, high fuel pressure, and the list goes on.

Again, both the P219A and the P2200 are related to bank one, so that is where the issue is.
So, I have a question. Are there any exhaust leaks? Do you have an infrared thermometer?

If you do, allow the engine to reach operating temperature. Check the temperature of the exhaust pipe before and after the bank 1 converter. See if there is a big difference in the temperature. If there is, chances are it is the converter.

If there is an exhaust leak before the converter, it will indicate a lean fuel mixture causing the computer to compensate by adding fuel. (The high fuel trim 33%)

Let me know.

Joe

Hey Joe, thanks again that sounds very good to me. I do have an infrared temperature thermometer, so I'll give that a shot and let you know. thanks again

Carl,

You are very welcome. It's tough not being there, so hang in there. We'll get it figured out one way or another.

Take care,

Joe

Hey Joe, sorry for the delay in getting back to you. I've been walleye fishing up in Green Bay Wisconsin. I'm back at it now trying to figure out this check engine light. I did take the temperatures on both caps and on the driver side the front was 450 and the rear was 460 and on the passenger side the front was 390 and the rear was 440. I'm guessing those are some good temperatures. I'm not sure you tell me you're the pro not sure why it says caps, but I meant catalytic converters.

Hi,

The readings actually are cooler than I expected. With the idea that the vehicle is producing high Nox gases (P2200), we are likely to have a vacuum leak specific to the bank involved. Have you checked all around the intake manifold and are you certain there is no pre catalytic converter exhaust leak?

As far as the temperatures, where there is a variation of approximately 200+ degrees, that usually indicates a problem. You are nowhere near that.

Recheck the intake for leaks where it mounts. Also, try this and let me know the results. Attach your scanner. With the engine at idle check the MAP sensor parameters. The readings should be between 2.7 and 6 PSI.


Let me know.

Joe

Okay, I will. thanks again.

Hi,

No problem, Carl. We need to get this figured out one way or another. LOL I look forward to hearing what you find.

Take care,

Joe

Hey Joe, I don’t have a live scan tool however the scan tool that I’m using the freeze frame shows the MAP sensor at 86K PA which I’m converting to 12.87 PSI.

Also, just as our information I did replace both MAP sensors and mass airflow sensors.

Hi,

With the engine running, the reading on the scanner should be approximately 8 to 9 inHg which is approximately 4 PSI. I'm questioning if the sensors you got are good.

Take a look at the attachment. It indicates the normal range of 20 to 48 kPa based on altitude. That works out to 2.9 PSI to 6.9 psi. You are double that.

Let me know.

Joe

See pic below.

Okay, I will check it out. After clearing the codes yesterday, I have now driven the vehicle forty miles and I have not gotten the light on. It makes no sense I would imagine it'll come on sooner or later.

Hi,

Do me a favor. If your scanner has a setting to check emission readiness, see if there are any circuits that are not complete. This just may lead us in the direction of the issue.

Let me know.

Joe

I went to O’Reilly‘s auto parts and borrowed their fuel pressure test kit. I think we may have found the problem. Let me run this by you. I applied the pressure gauge and key on engine off the pressure went to 60 PSI and then immediately fell down to 40 once I started the engine the fuel pressure went up to about 52 and then fell down to 42 and I could not get it the fuel pressure above 42. I put a load on the motor, and I tried to snap throttle I could not get it above 42 PSI. what do you think? I am thinking it's a bad fuel pump, however I will not sure how to test the fuel pressure regulator.

Hi,

I suspect you are correct. However, even a partially plugged fuel filter can cause the issue. Also, there is a fuel flow control module mounted above the spare tire. Basically, this module is what controls fuel pressure by changing the voltage to the pump based on need.

I attached a description below along with a test you can perform to confirm if it is good or not. However, this should have set a diagnostic trouble code.

Take a look through the pics below and let me know if you have questions.

Take care,

Joe

See pics below.

Weeks ago, I tried to buy a fuel filter for the truck, but I was told it was in the fuel tank along with the fuel pump, so I am assuming it’s all one unit. If I’d go the route and replace the fuel pump, do you have a brand you would recommend because I see online fuel pump cost range from $100.00 to $500.00.

I also assume that you would not believe it to be the pressure fuel pressure regulator, but the pump or fuel filter. Is that correct?

Hi,

As far as a brand goes, the OEM AC Delco brand would be the best, but those are likely the $500.00 ones. I checked out rock auto and the most expensive one was $390.00 and they started at under a hundred dollars. You may want to check the site. Delphi, Carter, and Delco are all good.

The one thing I would recommend is to stay away from really inexpensive online private sellers. I have fixed many failed pumps and other electronics that were a bargain. LOL

Regardless, you will need to know the fuel tank size and if the vehicle is designed to run on E-85 fuel. There is a difference. If you already know, tell me so I can get you the directions for replacement.

Let me know if I can help you in any way.

Take care,

Joe

Fuel capacity is 31 1/2 gallons and it is E85 and I replaced the fuel pump approximately five years ago, so I’m familiar with that procedure.

Hi,

Okay. I wasn't sure if you needed the directions. However, if you run into trouble, let me know and I'll try my best to help from here.

If you have a chance, let me know if the pump takes care of the issue.

Take care,

Joe

Hey Joe, I'm back. I ordered a fuel pump from Delphi about $300.00 and I just got it in. I cleared the codes and ran the motor about three hundred miles under 40 miles an hour and the check engine light came on I then put it on the highway and I drove 200 miles at about 60 to 75 miles an hour and the check engine light came on again.

Drove the car under 40 miles an hour and the check engine light never came on. Once I got on the expressway and went 60 miles an hour then the check engine light came on.

Drove the car under 40 miles an hour and the check engine light never came on. Once I got on the expressway and went 60 miles an hour then the check engine light came on

Well now, I drove the car probably 150 Miles and under 40 mph and the check engine light just came off.

Hi,

Is it always the same code and nothing different? With the engine idling the MAP reading should be between 19-42kPa or 2.7 and 6 PSI. Does it fall within the parameters?

Also, do you notice any ticking from the exhaust pre-cat which could indicate a leak?

Let me know.

Joe

I always get the same two codes the first is p 219a and then the second code is the one that caused the freeze frame, and it is p2200. I have a kPa 8 7 on the manifold pressure sensor. I do not have a live reading but if you recommend a code reader for active live reading I will purchase one.

Hi,

The MAP sensor isn't reading correctly. It needs to be between 19 and 42 kPa. Have you replaced it?

Joe