Poor performance

This can be caused by a bad MAF sensor which will not set a code. I would swap the sensor out to see what happens. Here is a guide and the location for your truck below:

https://www.2carpros.com/articles/how-to-replace-a-mass-air-flow-sensor-maf

This guide can help as well:

https://www.2carpros.com/articles/engine-has-low-power-output

Check out the diagrams (below). Please let us know what you find.

Cheers, Ken

Okay, thank you Ken. I will go pick one up today. I kind of suspected that might be it. Something I had done with my air filter was sprayed to much oil on it when I probably should not have used it at all. I likely baked oil on that sensor. Thanks

Hi Ken. Well, changed my MAF sensor. It didn't make a difference. A couple of months ago I had changed my pedal position sensor because I was having like a stall condition. I'm wondering now. Is there a right way and a wrong way of installing this sensor. It was the sensor only without the pedal that I installed.

If the sensor had a problem it would trigger a code. I am wondering if the fuel pump is going out. Let check the fuel pressure to see. Here is a guide to help us get started:

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

Pressure should be 46- 62 psi.

This guide can help as well.

https://www.2carpros.com/articles/engine-has-low-power-output

Please run down these guides and report back.

I do not think it is the fuel pump as everything is good under normal driving condition and would not cause it to keep revving after spinning tires. What I am thinking now is maybe the Idle Air Control Valve may be sticking. I only have this problem if I spin tires, the engine keeps revving a couple of seconds after letting off accelerator. Or if passing a vehicle engine will kick into high then back out right away and feel sluggish. If I am at a complete stop and I accelerate it goes like a charm. If I come to a rolling stop and then accelerate it doesn't kick in and feels sluggish. Other times while on the highway if I step on it. It just falls flat sometimes. I am unsure about this IAC as well because it idles good, runs good. Only when I step on it, and if I spin the tires as though something is sticking preventing the vehicle to return to its normal running operation.

The truck does not have an IAC, but a dirty throttle bore can cause the truck to go into limp mode. Run down this guide let me know.

https://www.2carpros.com/articles/throttle-actuator-service

Cheers, Ken

I have cleaned the throttle body already in and around the throttle plate. Do I have to take the throttle body right off and clean it? I do not think it is in limp mode either because well. I don't think it would run as good as it does. Other than what is going on.

Good afternoon,

Something caught my eye on one of your responses.

Do you have a K/N air filter in the system? you mentioned you sprayed oil on the filter?

Roy

It is a S&B air filter. I did spray K&N oil on it. But since had cleaned it again to get the oil out. It didn't make a difference. I made a call yesterday. I decided to take the guess work out and made an appointment at my local dealership.

Just for your information, those air filters that use oil are no good at all for computer controlled systems. they contaminate the sensors with the oil and all kinds of thing result from the oil.

If you have a car under warranty and you have an air filter like this, the warranty is null and void and the dealer will reject working on the car at all. that is how strong they feel about these types of air filters.

Keep us updated with your results.

Roy

I had just found out there are two types of filters by this manufacturer. Dry and one that uses oil. I'm thinking now that I may have a dry filter and used oil on it and ruined my filter. I have contacted S and B filters to find out whether it it is a dry one or uses oil. Thanks for the info on that. I will be replacing it with a dry one. If I can get it.

I would just get a good quality filter such as AC delco and go with that.

Roy

I have thought of that. It would make it a lot easier replacing my filter when needed. But, I have no wrecking yards close by. I would need some original parts to switch it back. Maybe I will go for a ride today and go check on someone I know. He may have a truck there that I can get what I would need. Thanks. I will do that.

You are welcome.

Always glad to help.

Hello, well I had switched everything back to original. Box, tube and filter. Only now that I did that I am getting a real hesitation like it wants to quit then slowly regains if I were to step on it and try and spin my tires in the snow. I took it to the dealership yesterday and they couldn't find anything wrong. Reason being they were locked out unable to retrieve anything because my computer was altered. Performance chip. The person I had purchased the truck from did the programming and I have no idea of the type of programmer he used. But I am thinking that because there was a cold air intake on there with a big filter that the programming calls for that amount of air now and is not getting enough air through the original filter and tube. I had just ordered a replacement filter for this cold air intake. This one is a dry filter. But I am still wondering of any other possibilities.

Okay, the next step is to have the chip removed and get it back to stock.

then you can access the PCM and see what the readings are for all the sensors.

Roy

Something I want to ask. When I purchased this vehicle I had problems with my accelerator pedal position sensor. I had changed the sensor only. Without the pedal. Is there room for adjustment on this sensor? If so how can I adjust it?

No, there is no adjustment.

What was the code that was set when you had this issue?

There is also the throttle body as well.

Roy

I don't remember the code when I replaced the sensor. I just know that it solved the problem at the time. Before I replaced this sensor at times I was getting no throttle response when trying to accelerate from a stop. Like it was stalling almost. So I replaced it and it solved that issue. I don't have any codes right now. But I am thinking this must be off by half a degree or something. I don't know if I still have the old one. If I did I would maybe put it back in and wait until code is set. But if there is a procedure on setting this it would likely be worse than it was originally. Just looking to know. Can this sensor be adjusted?

As I stated in my last response, no. it is not adjustable. it is a plug and play sensor.

Roy

Hi Ken. Well, I didn't have a newer type of fuel pressure tester but picked one up yesterday. It is confirmed about the fuel pump. The pump itself is good but the regulator must be leaking. I tested it just awhile ago engine not running or cranking. I was doing it myself and never got initial reading but the reading I did see was up then slowly went down with key on. Unfortunately this regulator thingamajig along with filter are all in the tank. This technology sucks. From buying one thing to having to buy everything all at once. I hope this will solve all of my issues. But thank you for leading me in the right direction.

Fuel pumps go out in these cars. here is a guide to help walk you through the process and diagrams below to show you how to do the job on your car below:
.
https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

Check out the diagrams (below). Please let us know what happens.

Hi Ken. Well I had replaced my fuel pump, as well as my throttle body which had the TPS installed already. I hooked up a scan tool and got some readings from my fuel trims. They are STFT B1 -0.8 to -3.9 LTFT B1 11.7 STFT B2 -3.9 to 1.6 LTFT 4.7 to 5.5 There is a spike with all of these numbers that jumps way up to 93.8 for a second or 2. My O2 readings are O2S STFT B1S1 34.4 O2S STFT B1 S2 99.2. I haven't looked yet or tested but I'm thinking a vacuum leak somewhere. Just wanted your opinion on these readings. Or on why I would get such a spike in my reading to go up to 93.8%?? These readings were taken with the engine warm and at idle.

I'm still having the same issues.

A vacuum leak make sense lets try this guide to see if you can find anything.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Hi, its Roy again.

The long term trim on bank 1 is too high. That does indicate a vacuum leak on that bank only.

I would think of the intake manifold gasket as that is common only to bank 1.

Remove the oil fill cap and put your hand over it while the engine is running. See if you feel vacuum there.

Roy

Hello. I did a test a few days ago with my scan tool and watched my fuel trims again. I did it at idle then at 2500 rpm. I didn't see any numbers going down. I did see a number or two going up. I do not remember which of those it was or how far it went but. Going up isn't that different from a vacuum leak. If I had a vacuum leak would it not run rough at idle? It does not run rough. I haven't done any test yet for that yet due to the whether being cold also this test I did points me in another direction Also...I am still unfamiliar using my scan tool but..I cam up with a bunch of codes that wouldn't show up just using a code reader. The majority of them point to transmission codes. With so many codes I am wondering where to look first. The TCM or the PCM or ECM. Majority of those codes were P08 type of codes. I also got a P0900 and a P090C which points to the clutch actuator circuit for 4 wheel. But this does work Along with some U type of codes Like U2608 and U1108, U3A08. There are others. I'm not sure but I think they have to do with current supplied to a component. I do not know where the TCM or PCM or ECM are yet either to begin looking at the wiring and ground. But I think all of what is going on now is some bad wiring or one of those modules is cooked.

You cannot test a vacuum leak to the intake with a scan tool. That is impossible.

You need to address one issue at a time.

You need to do the test I suggested.

Roy

Are you telling me you cannot tell if there is a vacuum leak using a scan tool??? That it is impossible???

You can tell by the long term trim readings but the scan tool will not tell you where it is located. thats good old fashion diagnostics.

Roy