I have a 2001 F150 4x4 w/ 5.4 L I have K&N intake, throttle body spacer, and a diablo sport delta chip. Well I opened up the exhaust with some hi-flow cats, I took the four off and had 2 magnaflow hi-flos put on and they go into a single in dual out muffelr with dumps well the truck runs real rich now. Any ideas? I've tried taking the chip off and nothing changes

 

HI! HAVE YOU CHECKED THE BARO PIDS FOR PROPER READINGS? THE MAF MAY BE DIRTY OR HAVE OILY DEPOSITS ON IT. DEPENDS ON WHAT ALTITUDE YOU LIVE IN. IN OUR REGION IT WILL READ BY DEFAULT AT 157. IS IT RUNNING ROUGH & SMOKING REAL BAD? UNPLUG IT & SEE IF IT CHANGES.

 

I'm leaning toward a contaminated Mass Air. Not uncommon for oil from a K&N filter to foul the meter and cause all sorts of problems. Clean the meter with an electronic cleaner or one of the specialized mass air cleaners on the market. If this is the problem be conservative when applying oil to the K&N in the future. Good Luck

 

No its not running ruff. Its just lost some low end power and my fuel mileage dropped drastically I used to get like 16 in town and 18-19 on the highway now Im gettin about 11 evrywhere and its just not near as powerfull as it used to be. I live in central texas so its pretty flat out here if that makes a difference. And it doesn't smoke that i know off but my buddy says when i drop a gear on teh interstate like to pass it does blow some smoke. And when I had tips I had quite a bit of carbon build-up on them.

 

The point many miss is that mods tend to enhance hi rpm and lose low end torque.
The OEM exhaust is tuned/designd pretty well for low end and overall operation.
It's a truck!
You just took that all off.
Next; what happened to the OX sensors?
If they are not hooked up/faulty etc, the engine runs on rich fuel tables by default, as a backup.
Old saying, you play-you pay.

 

The ox sensor are still there they weren't removed or anything but I will definitely check them out and see how they look. Thanks for the advise.

 

Syptoms point towards bad o2 sensors. I believe a fouled MAF will normally result in a lean condition, not rich. Just the opposite w/ o2 sensors.

 

You're right about the Mass air usually causes a lean condition but I have seen rich also. As you may have noticed I advise cleaning the Mass air quite a bit on here. One it is easy to do with no expense involved and two I have seen it solve all kinds of problems from Lean condition, Rich, Rough idle, poor performance you name it. To me it's just a quick,simple try this first kind of advice. I have seen guys completely frustrated with their vehicles simply try this and the problem was solved. Take care.