Engine RPM/Power Loss K&N Cold Air Intake-2003 Tacoma 3.4L V6

I have 140,000 miles on my 2003 Tacoma 3.4L V6. I've recently experienced power loss and slow acceleration so I purchased a K&N Cold Air Intake to boost the hp. This helped, but from time to time I would begin accelerating from stop and have the pedal to the floor, but RPM's/speed would not increase. I cleaned the mass airflow sensor but to no avail. Since this is obvioulsy dangerous pulling into traffic, I removed the cold air intake. Does anyone have any thoughts on the power loss and why the cold air intake did this? Even with the stock air box, there seems to be less power than normal.

Thanks!

 

the only thing that comes to mind quick, was way back when i had a mustang gt the first mod i did was the steeda intake, and i did not put a vacuum line back right, and it did about the same thing, and sometimes it would throw the CEL and sometimes it did not.

now it that the oiled air filter? is for take it back, and get your money back, I'm sorry but oiling that filter was way more trouble than worth.

 

When was the last time you changed the plugs

 

Like 2004TacoPrerunner asked, when was your rig last maintained? I would start with the easy, simple stuff first: spark plugs, spark plug wires, and fuel filter. Have you ever cleaned your intake? That may help also.

You purchased the K&N after the power loss right? That being a fact, the air filter doesn't have anything to do with it.

Any funny noises under the hood?

Starts and idles perfectly?

 

Plugs and wires are about 2 years old. I've had a K&N filter in the stock air box since 2003. Why would K&N sell a cold air intake for the Tacoma, knowing the oiled filter creates problems. K&N did refund my money, but didn't require me to send the intake back. I'll try cleaning the mass air flow sensor again, as well as the intake, then reinstall the cold air and make sure all the vacuum lines are nice and tight. Thanks all for the suggestions. If anything else comes to mind, please let me know!

 

Cleaned the maf sensor yet?

 

Quick thought, sometimes my idle drops below 800 RPM on hot and cold days. Maybe this could be related?

 

Just me, but here is what I'd do. I tend to do the free/cheap stuff first and then work into buying parts as needed. I assume there are no codes stored to guide so here goes.

First, right or wrong, I'd read some testing on cold air intakes in the deck plate mod threads, that suggest (at least in the results given for testing on a Tacoma) that they do not help. So, I'd put the stock airbox and a good clean stock type filter on it.

Then to the power loss. As suggested I'd look at maintenance issues first. Disconnect the battery.

Clean the maf. Plenty of good posts/how to's on here. Basically though, clean it by unplugging it, remove it and just flush the dirt off with the maf cleaner spray. Do not wipe/touch the little wire in there or you'll damage it and be stuck buying another maf.

Next clean the throttle body. I do this by removing it. Takes a bit of work, but not hard. Allows you to also carefully get into the top of the intake and get the potential sludge out of there too. Amazed at how much was in mine when I got the truck.

While the throttle body is off you can remove the idle control valve and clean it up and check operation.

Do you have a good meter to test parts with? If so I'll search up the links and post how to test the idle control etc. for you.

Check all the vacuum hoses while you are there to ensure none are cracked, loose or brittle. Replace/repair as needed.

Once all back together, I'd just have a look at your battery connections too. Ensure clean connections at the battery and also ensure you have a good connection to the alternator and clean and tight connections to ground to the chassis/engine.

Generally give all the connections etc. on the truck a once over and sure they are tight and clean. Look for any signs of arching on the ignition system. Check condition of the plugs (what plugs did you put in? correct ones?). Generally verify the system.

At that point I'd button everything up and start up the truck to have it reset the idle etc. Drive it normally for a week or so and see where you are with it. Any improvement. Then I'd fill it up and throw some Chevron Fuel System cleaner in it and run it through.

If still an issue then I'd get into replacing the fuel filter (tend to throw on a new cap too just to ensure a good seal) and on from there. Should be a good start.

Diagnosing can be challenging, but could end up being something simple like the above. Beyond that, testing sensors, compression issue perhaps, timing, plugged converter etc. come to mind, but would think that a CEL would have popped with some.

Any change in the mpg that might have occured around the same point the power loss happened? Just free thinking, but got to wondering about a faulty temp sensor.

Anyway, try the basics and let us know what you find.

Plenty of good people on here willing to help and your results posts might help someone else in the future.

Cheers