Hey guys! Was on my way to the office this morning and engine light came on - Monday go figure! I pulled over ran diagnostics pulled P0171 System Too Lean Bank 1. English please? Cleared code, drove the remaining 10 miles to work with no code. Any comments? It was 20 degrees and wet this morning if that matters, seems to jack with the four wheelers, but who knows. Thanks.

 

I don't think it's anything to worry about. Being that cold and if you have changed the settings on your fuel, that might be whats wrong. But I might be wrong.

 

04's like yours and mine come from the factory running a little lean. If you "K&N system" is a CAI kit, then you really need to get that Evo upgraded to a Gryphon and custom tuned to get her dialed in to run right. Running lean for a long time could cause damage to your engine.

 

What year truck?
How many miles?
How long have you been using the edge?
What tune were you using?
Did you load a tune within the last 2 weeks?
Sorry to ask about year of truck, I'm on a mobile and can't see it.

 

He has an 04 with a K&N. So he is running lean.

You need to get the CAI off there untill you can get custom tunes. The Edge is for stock intakes only!

 

What he said.

Before I upgraded to my Gryphon, I got put on Edge's "list" to get an upgraded tune to accommodate a CAI. Been 2 years, never heard another word from them. Thank goodness for http://www.phptune.com and their top notch service.

 

The truck is an 04 5.4. All I have on is the K&N air filter, I have not put on the CAI part yet so I am still on stock intake. I have not changed the tunes in the last 6-months and am running canned stage 2. The truck has 114,000 miles. I am not gonna worry too much about it unless it keeps throwing codes but was hoping it was the same as another time when I kept throwing a check fuel cap warning, but that went away and never came back.

 

Ok, so you have the dropin filter. No, that should not cause the lean condition. Have you changed the plugs? There is a cooler plug that should be used on the 2004 and 2005s.

 

This is exactly why I should have got involved with this site in 2004! I am finding new things out about this truck all the time. The plugs are on the to-do list, but frankly I have heard horror stories about changing them, so quick answer is, No I have not. This is the first vehicle I have ever had long enough to even pay off, let alone think about changing plugs. When should one do this? As far as the code, I guess I will just wait till the drive home tonight and see if it throws the code again. Thanks for the help and suggestions, keep 'em coming! I have learned a lot about this truck in the last 6-months since reading up on here, well except the whole Cummins swap - and well that was worthless! lol

 

The plugs should be changed at least by 100,000 miles. I suspect that may be your problem. You need to read up on the TSB and either follow in explicitly, or take it to a dealer that knows what they are doing. Other things that probably need attention are cleaning the MAF and the throttle body. In fact, with the K&N dropin, you need to clean the MAF on a regular basis. I do mine about every 20,000.

 

There is a new tsb suggesting the plugs be changed out well before the 100,000 mile mark.
It suggests between 30k-60k but this is for ease of removal, not for failure.
Like Bluejay stated definitely look into cleaning the MAF and TB. There are threads on these subjects located in the "How To" section of this forum.

 

Bluejay and 88racing are right on target. I changed my plugs in my 04 myself, followed the TSB step by step and didn't break a single plug. Patience is a virtue!

 

I was also going to add in that using the search feature on the forum can be quite educational. Just type in the DTC code # and read. Just pay attention what year trucks and engine size they are posting about. There is a lot of information on this code.

 

Well it looks like I have some reading to do! Thanks guys!

 

I have the same problem! I have all the same stuff as you, drop-in, and the evo. But my truck is a 2001. I have the same codes thrown on bitter cold mornings, we'er talkin like 10-15 degrees. I will try cleaning my MAF and TB to see if that helps.