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2007 Chevrolet Silverado 1500 Question: 2007 silverado check engine light. installed colde air intake. system too lean.

 

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Church1, Watertown, NY, November 17, 2013, 09:15
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i installed a cold air intake on my 2007 silverado new body style 1500. check engine light is on and have diagnostic codes. system too lean. the filter is huge. If i installed a smaller filter (less airflow), would that solve the system being too lean issue? would make sense to me...big filter=lots of air, smaller filter=less air. just curious

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    pushrod November 17, 2013, 09:32
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    If you are now going to try and reduce the air flow, why did you try to increase it to start with? Do you still have all the sensors like the MAF & IAT working as they should? What was wrong with the stock system? I just dont see the need for that add on. Never pay for itself. That's my opinion, i could be wrong! It's your truck, do what you want to.

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    Church1, November 17, 2013, 09:51
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    ya funny you mention that. i bought the system when i was deployed...sounded like a good idea. installed it...check engine light came on. unfortunatly..im an idiot and got rid of the stock air system. just looking for the cheapest most effective way to fix it. nothing was wrong with the old system...just looking to get better airflow...now im getting too much lol. the MAF and all that still works. just thought if i went from a big filter to a small filter...would that remove the system too lean codes.

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    pushrod, November 17, 2013, 11:23
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    How long has this breather system been on it. Check engine light come on right away, or after a good bit when it was installed? Which engine you got?

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    ProfessorG, November 17, 2013, 15:12
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    Bet he has an air intake leak.

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    pushrod, November 17, 2013, 16:01
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    That's where i was headed! Need to know what engine. 5.3 little worse than the other 3 i think.

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    Church1, November 17, 2013, 17:01
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    alright...so..the check engine light came on...the same day i put it on...MAYBE..the day after. i have checked and cleaned everything...took the throttle body off...cleaned that...it was loaded with oil due to this damn thing. i took the MAF sensor off and cleaned that with the "special cleaner". the tubing on this damn thing is at least 4in. the filter...is almost 6in where it connects to the MAF. I think the filter is wayyyy too big for it. idk...im a backyard mechanic...i dont understand these new cars or trucks...im trying....but its all electrical. i think im just gonna toss this crap and buy the stock airbox for it. IF i cannot get this resolved. the engine is a 5.3. its been on for a year or 2. but its throwing off the traction control...according to the dealership....which...partially they are right...i have been doin my own diagnostic with this damn thing for too long....im getting beyond irritated...you know. i do appreciate you guys responding.

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    pushrod, November 17, 2013, 17:09
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    I think getting all the stock componets is your best bet, never did like those "cold air" type air cleaners! Nothing but trouble.

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    Church1, November 17, 2013, 17:13
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    your right...wasted my damn money.....but....SUPPOSEDLY...they help and improve so many things.im just irritated you know. BUT then again...thats wat i get for buy off brand crap.

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    pushrod, November 17, 2013, 17:26
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    Man i dont know about you but from what i have read here now, just put the damn thing back like it was! Beats all i have ever seen!! You will see what i mean. wtf.

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    Church1, November 17, 2013, 17:43
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    hey my dad always said....and im sure everyone can relate...if its not broke...dont fix it.. thank you guys for getting back to me.

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  • Answer #2

    cardocIII from Gillespie's Auto Service, November 17, 2013, 17:20
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    This isn't the first time that I have heard this and the potential answer can be difficult to grasp. The MAF sensor doesn't actually measure all of the air entering the engine, it is calibrated to measure a portion of it and that is supposed to give the computer an accurate representation of all of the air entering the engine. Saying this another way, picture all of the air flowing into the engine via the stock 3" pipe. At a given engine load it would be moving at a speed that the sensor reads accurately because the engineers calibrated it to do that. Now take that same sensor and put it into a pipe 10% larger, and with the same engine load as the first example, the air in the pipe would be moving 10% slower, so the sensor ends up under-reporting the airflow to the computer by that same 10%.

    Now that's actually the easy one, there is another that often occurs. Air has mass, and because of that has inertia. As it moves through the air filter and into the intake tube where the MAF sensor resides the engineers do everything they can to make it have a linear flow through the entire tube. But if turbulence occurs, especially if it is right at the MAF sensor, the sensor could experience a high spot, or a low spot in the density of the airflow. Turbulence/density issues are often erratic under different engine loads and it often takes plotting data in a scatter graph format to prove when it is occurring.

    So what do you do? The first choice is to re-install the original intake system, but I already saw that you discarded it. So that brings you to the second and tricky choice, I'll try and explain this the best that I can. Your solution might be to install a baffle in the tube exactly opposite of the MAF sensor. The aim is to decrease the cross-sectional diameter of the tube right at that point. That will speed up the airflow and increase the value that the sensor outputs for a given engine load. It's going to be a trial and error exercise, and you must be absolutely certain that the device remains secure and doesn't get ingested by the engine. To do that, you have to make it in a complex shape. It needs to have a curve to follow the profile of the pipe, and a second curve to make it rigid, and you still need angles to anchor it to the outside of the pipe. To attach it to the pipe, first draw a "smile" on the pipe to be the line that you have to cut. Three inches in length will be plenty. Bend a piece of tin to be the baffle in the shape of the smile that you cut. Then cut it to match the profile of the pipe and leave it about 1 3/4 inches high. Cut 3/8" ears and fold them every other one forward, and rearward. That will be the outside of it and prevent it from being able to be drawn into the pipe and make for an anchoring system.

    If you have the picture of what the baffle will look like, the first adjustment to it might be to ensure you physically clear the MAF sensor. Then you can secure it temporarily with duct tape. Now its all down to adjusting the size of the baffle to force the MAF sensor to read correctly and you will have to do some extensive driving under multiple conditions while tracking the long and short term fuel trims. If the sensor is over reporting, you'll have to start whittling it away. If it's still under-reporting you'll have to re-make it larger and start the process all over again. It's fun to re-engineer some things, but it can be very frustrating learning the ropes.

    Once you have the fuel trims accurate, you can then secure the baffle to the pipe, pop-rivets in about four of the tabs should do. Then seal it up with the duct tape again.

    HTH.

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