K&N cai and magnaflow killed my miliage/power!! Help

[MikeyAces]

Put a K&n intake (FIPK) on my truck, 03 yukon, have an magnaflow muffler installed and I lost power and it killed my miliage. Between the 2nd and 3rd upshift it just bogs and does not want to rev. Seems boggy all around unless I stomp it and it gets to about 3500 r's then reves up quick. Filter is cleaned, fresh tune up. 108k on it.

Seems like to much air for the stock computer.I plan on getting a black bear tune in the spring.But right now kinda bummed.Any suggestions?????

Thanks MIKE

 

[RenegadeTahoe]

Put a K&n intake (FIPK) on my truck, 03 yukon, have an magnaflow muffler installed and I lost power and it killed my miliage. Between the 2nd and 3rd upshift it just bogs and does not want to rev. Seems boggy all around unless I stomp it and it gets to about 3500 r's then reves up quick. Filter is cleaned, fresh tune up. 108k on it.

Seems like to much air for the stock computer.I plan on getting a black bear tune in the spring.But right now kinda bummed.Any suggestions?????

Thanks MIKE

Check your plugs / wires... sounds like you're not firing on all cylinders...

 

[boostaholic]

Check all your connections, mass air sensor, plug wires, everything. 100s of people have done the same mods with exceptional results.

 

[RenegadeTahoe]

Check all your connections, mass air sensor, plug wires, everything. 100s of people have done the same mods with exceptional results.

^^^^ yeah, that too. :thumbsup:

 

[DarkTahoe00]

Check around the TB the K&N's are prone to come loose there so make sure it tight,and like boost said check everything!

 

[bahollis]

+1 on the K&N install.

I was throwing a code (low MAF voltage), so I took the entire K&N assembly off and cleaned it, and re-installed it. It might have been me cleaning the electrical connection to the MAF that did it, but I reseated the intake and made sure it was all tight. I was having that "bogging" feeling too in lower gears. No problems since.

Check the MAF sensor to make sure it's not damaged (i.e. broken or bent wires)

BH

 

[rockman20]

Sounds like everyone agrees. I would check the connection from the CAI to the throttle body and make sure there are no leaks. I would also check the MAF and make sure that did not get damaged. Get some MAF cleaner and clean it since you are looking at it.

One thing I did on my Trailblazer and I plan on doing on the Yukon is cleaning the throttle body. It is not hard to do. Remove it, clean it really well, replace. I didn't notice any real big gains on the TB, but they do get quite carboned up in there. Which still amazes me with a dry intake.

 

[HitandRunDriver]

Sounds like everyone agrees. I would check the connection from the CAI to the throttle body and make sure there are no leaks. I would also check the MAF and make sure that did not get damaged. Get some MAF cleaner and clean it since you are looking at it.

One thing I did on my Trailblazer and I plan on doing on the Yukon is cleaning the throttle body. It is not hard to do. Remove it, clean it really well, replace. I didn't notice any real big gains on the TB, but they do get quite carboned up in there. Which still amazes me with a dry intake.

+10000

there should really be no reason for you to lose power if you installed everything properly

 

[MikeyAces]

just did a tune up over the summer. new plugs wires, fuel filter. The only thing I can think of I seafoamed the truck before winter...do you think I f*cked up a plug? Seafoam did not seem to make any differecne.

Seems to run better now, I put the stock airbox on and used the k&n tube.Little more responsive. Still boggy if I get on it between 2000-3000 rpms's.

I have delco iridiums in it. Maf looks good. I have just cleaned it with the spray, no difference.Never get and trouble lights. Should I disconnect the battery and let the computer reset or put new plugs in it?Does not sound like it has a miss, runs and idels smooth. Driving me nuts!!!!!!!!!1

 

[02tahoeindiana]

had the same problem.
some gasket on the throttle body was shot.

 

[MikeyAces]

had the same problem.
some gasket on the throttle body was shot.

How'd ya know?Was it running rough? not idleing?

 

[02tahoeindiana]

it was running rough. but most notably it loped at idle. and barley stayed alive.

 

[JennaBear]

I agree with the above, these aftermarket intakes have a tendency to wiggle themselves loose and more times than not is the culprit. A dirty MAF or a MAF with intake oil on it would be my second guess.

 

[MikeyAces]

I agree with the above, these aftermarket intakes have a tendency to wiggle themselves loose and more times than not is the culprit. A dirty MAF or a MAF with intake oil on it would be my second guess.

Have a good seal double checked it.I have just cleaned the MAF but I did not clean the plug for the maf.Don't know what else to try. Gonna disconnect the bettery for a while and try that. Running to smooth for an intake leak, very smooth idle.:confused2:

 

[notch8]

I opened the hood after hearing a rattle and to my horror last week my K&N intake tube was completely off the throttle body.

 

[rockman20]

Yanking the battery cable might do the trick. It is possible to that exhaust and intake at one time was a big change for the computer. They take a while to re-adjust themselves to the new conditions.

I have heard this is how most people find out about their dirty throttle body. They replace the battery or have the battery disconnected for something and when they take it out afterwards, the vehicle behaves poorly. The computer had slowly adjusted itself to the old, dirty, throttle body and now it has to re-learn and re-adjust to that again.

There has to be something simple. The CAI tube doesn't have an obstruction or something stupid like that in there does it? Or the filter? You didn't accidently knock a sensor wire off while doing either upgrade? It has to be something like that!

 

[MikeyAces]

Yanking the battery cable might do the trick. It is possible to that exhaust and intake at one time was a big change for the computer. They take a while to re-adjust themselves to the new conditions.

I have heard this is how most people find out about their dirty throttle body. They replace the battery or have the battery disconnected for something and when they take it out afterwards, the vehicle behaves poorly. The computer had slowly adjusted itself to the old, dirty, throttle body and now it has to re-learn and re-adjust to that again.

There has to be something simple. The CAI tube doesn't have an obstruction or something stupid like that in there does it? Or the filter? You didn't accidently knock a sensor wire off while doing either upgrade? It has to be something like that!

No nothing is blocked.Im pretty mechanical thats why this is bothering me so much.I paln on doing the battery thing tomarrow and give it a try. Don't know why im having issues. If somthing was wrong would'nt it trip a trouble light, like if the MAF was bad or something.

Getting very aggervated with this problem! Everyone has done these upgrades with no problems at all with good improvments.:confused2::confused2:

thanks for everyones help!!!!!!:thumbsup:

 

[jwesenck79]

did you ever figure this problem out?

 

[tybardy]

i have been following this thread pretty close as i have very recently upgraded my intake setup and have a magnaflow sitting in my garage waiting for install (hopefully this weekend)

It sounds like the problem started after you installed the intake right?

I finished putting on my intake tube and modding my intake box last week and have been driving quite agressivly since... I do not think i can feel any performance gains to speak of, however i can HEAR a difference, my motor sounds much meatier arount 2500RPMS....


i was thinking though, after driving it like this that the "meaty" sound i have been hearing is actually the motor bogging out just a little bit, maybe to much air and not enough fuel... or something... not sure.


Its not that bad and i think it might just be in my head because i really cant feel any difference in performance either way...

 

[MikeyAces]

did you ever figure this problem out?

another guy told my about a thing called tourque managment. I guess GM put it in these trucks to prolong the drive train. When you get on the gas the computer retards the timing alot! He also had a bunch of graphs too.Could not believe it. Your never getting close to the claimed hp. It was a link off this site just cant remember where. Im just gonna get a bb tune in the spring, I heard it does wonders and that should make me happy!!!