K&N air filter

[GMC or nothing]

My 2010 1500 has the 5.3. I installed a K&N air filter after about 1/2 tank of gas and my gas mileage dropped from 18 to 10. I am driving the same roads. Could the air filter be confusing the computer and causing this?

 

[Molson02536]

My 2010 1500 has the 5.3. I installed a K&N air filter after about 1/2 tank of gas and my gas mileage dropped from 18 to 10. I am driving the same roads. Could the air filter be confusing the computer and causing this?

If you over oiled your K&N this will do it and in the winter also will cause this. The oil in the filter get's thick in the winter and restrict the air flow, so it's a good practice to replace the filter again in the winter time with the paper ones.

Make sure you have not accidentally disconnected any of the sensor wires along the intake tube. Try this if everything seams to be in working order, with the ignition switch turned to the on position "engine not running". Pull the ECm fuse out for 1 min and then place back in, turn the ignition keys to the off position and turn the key to the run position "engine not running for 30 Seconds" this will also reset your IAC then start the engine.

If the engine stalls, let it and don't touch anything. Just start it up again and let idle for 3 min then go for a test drive. The PCM is relearning all the sensors again like the first day i was started at the plant. Your mileage should be back to normal if not better if you can keep your foot of the skinny peddle, remember the air can enter your engine much easier then before so your fuel injectors will fire longer duration of fuel for more HP rating.

If it's fuel and performance your looking for to get, your going to have to finish off when you started by replacing the restrictive exhaust by replacing it and getting your PCM reprogrammed for the intake and exhaust changes. Once you have done that you'll real feel the difference in performance and better gas mileage.

My Jimmy with the intake and exhaust done with a custom PCM tune, i went from 19 MPG to 22 MPG and almost 23 if i stay around 68-72 MPH with the air conditioner. Here are a few links for you to look read and decide what's best for you.

http://www.pcmforless.com/
http://wait4meperformance.com/
http://www.magnaflow.com/

 

[GMC or nothing]

Man that is great advice. I will do that. thanks again man.

 

[Z15]

I don't know what you were hoping to accomplish with a K&N air filter but unless you have modifications up the ying yang, the stock air filter will give you all the mileage and HP the engine has to give.