Will do Rob.. putting both upstream o2 sensors in this coming weekend. Haven't seen any change yet, throttle body cleaning caused truck to high idle. Unplug batt to reset system, now it needs to relearn clean throttle body.
Rob R. wrote: Excellent idea. Those KN filters are notorious for fouling the MAF sensor with oil.
I have never heard that about K&N filters, I ran one on my pickup for about 6 years with not an issue. It wasnt for performance my reasons for purchase but cost savings. Instead of buying new air filters i bought one and cleaned it every so often. You can only shop vac out a paper filter so many times. 50 bucks up front probably saved me 50 to 100 bucks over the duration I owned the truck. I can see where the oiling of the filter can cause some people some problems if they over do it or not take their time and let it sit for awhile after spraying.
Some mass airflow sensor/intake tube designs are more sensative than others. Your point about improper service and over oiling is correct...you are much more likely to have an issue if the filter is over oiled.
When it rains it pours Truck mpg has plummet prior to putting o2 in it, it's now going to garage to be service this week. SES light on, Scan shows rail pressure sensor and fuel pump. Tested on pressure shows drops and gains in fuel pressure. Four months ago shop install new fuel pump and fuel module that cost $$$. Good news fuel pump and labor is covered, rail sensor will be my bill. O2 sensors are in tool box waiting for another week. Check back next week for out come
Today truck finally gets fuel pump replace and rail pressure sensor. Mpg dropped to 14.4 with highway and city driving. Improvement to 17.3 after installing o2 upstream sensors with same commute. Hoping to get little better after fluctuating fuel pressure gets resolve.
Is the fluctuating pressure causing any driveability issues? If not, save your money.
17 mpg is pretty damn good for a 5.3 .... if that's what you've got. I've got that with 3.73's, and 16 is the best I've seen. I usually see 15.5 highway or city, summer or winter, but then MA has the shittiest fuel in the northeast, so our numbers will be a couple MPG lower than most. We managed 17 mpg out west doing 85 mph due to the better quality ETHANOL FREE fuel out there.
SMITTY wrote:Is the fluctuating pressure causing any driveability issues? If not, save your money.
17 mpg is pretty damn good for a 5.3 .....
Yes got 5.3. 4x4 Engine light is on because of it. Truck is little sluggish and exhaust smells rich. I've gotten 22.3 mpg on trip to Kentucky. Since last post mpg drop to 16.7.. appointment was cancelled for next week do to work.