I have a 99' w/ the 5.4L engine. Engine is all stock except for drop-in K&N air filter. I bought a Superchips (model 1715) power programmer and have had problems w/ pinging under moderate exceleration and when towing. Pinging occurs on all programs (87 octane, tow and high performance). Anyone else have this problem? Any solutions? I live in California and Superchips said it may be related to the gas in Califonia (clean-air restrictions). They offered no solutions... great customer service!

 

Have you tried 91 octane or higher? I use the Superchips programmer and it requires 91 octane for the performance mode.

 

Yes... I even tried using 91 octane w/ the 87 octane program and I still got pinging. I also tried adding octane boosters to 91 octane... still pings!

 

I know there is a sensor that is supposed to prevent the pinging. I can't remember what the proper name is but maybe your sensor is bad.

 

How many miles on your truck? Have you changed the spark plugs and wires?

 

102K miles... yeah, I had the 105K mile sevice done by the dealer. In that service, they replaced the plugs and wires... still pings!

 

My expy pings like a @#%!@# too when under moderate loads. This includes little things like just going up slight hills. When towing anything it pings so bad that I'm afraid that it'll throw a rod out the block unless I use super and even then it still pings a little. If I run mid-grade in my daily driving then it's not to bad, but will still ping on occasion. I've noticed the pinging is worse in summer than winter so maybe the fuel blend does have something to do with it. We get oxygenated gas (methanol?) here in the winter. Or maybe it's the colder weather that does it.

From what I've heard these things do have a knock sensor on them and they are fairly easy to change, but I haven't gotten around to digging up any info on it yet.

As far as I know my expy is completly stock.

I just checked and NAPA lists the sensor as a Detonation "Knock" Sensor and the OEM replacement is $32.99 guess I'll figure out where this beast is located and see about replacing it.

 

Pitrow...thanks for the info. I will look into replacing the sensor you mentioned... I wonder if this sensor commonly fails?

 

cdarrenp, does your truck still ping when you revert to the factory tune?

 

I also had another thought, you might be wise to run some seafoam through the motor and see what that does for ya.

 

MisterCMK... no pinging when in the factory tune. I hope I don't sound stupid... but what the heck is seafoam???

 

Seafoam is a chemical that you can run in your truck either through a vacuum line, the crankcase or the fuel tank. I would put a can of seafoam in the gas tank next time you fill up and run it through a vaccuum line per directions on the can. It breaks down carbon buildups and sludge and junk in the motor. I've found that my vehicles run better after running it.

 

When did you last change your plugs?

 

MisterCMK: What vacuum line do you 'pour' seafoam into? How do you perform that procedure? While it is running? How much do you use from the can?

cdaRRemp: For the 105k mile service; what 'wires' were replaced with the plugs? Doesn't it have COPS?

 

Yes, 5.4L's have COPS, not wires.