Can old ingnition wires cause p0171?

[Paul G.]

Hi all,
After cleaning my maf sensor,reset pcm P0171, 20 miles later code came up again,hesitation was a whole lot less,still there a little bit.sprayed carb cleaner,about half a can looking er listening for vacuum leaks, nada.Could bad ignition wires cause this?If i ever so slightly press the gas pedal it sputters abit,nothing like before maf cleaning.The wires look old,I know shiny new ones can be bad to,but possibly it misses a low rpm spark and gives a lean condition?Thanks in advance Paul

 

[BrApple]

[FONT=arial,verdana,helvetica,sans-serif]P0171[/FONT][FONT=arial,verdana,helvetica,sans-serif]System Too Lean - Bank No. 1. [/FONT]

sounds like it maybe time for an O2 sensor ... or there is a vac leak somewhere ...

 

[Paul G.]

Hi BrApple,
You gave me some good advice earlier today in my resetting eec thread.I have replaced both 02 sensors,spark plugs,cleaned maf sensor and elec connections,and #13 fuse(it was blown)got rid of all codes exept p0171 keeps coming back.I tried to find a vacuum leak by spraying carb cleaner everywhere,couldn't find anything.I read in another post a guy had a p0171 auto zone said it could be from a misfire.I know autozone isn't reliable for diagnosing but was wondering if old plug wires could do it.I also really cant get access to pcv tubing to spray it and visually inspect.I'll try wires the change pcv (I heard it's a PITA).Please let me know what you think about the wires set theory,as the car isn't exactly super peppy off the line.Thanks Paul. Also where is the vacuum canister located I'll try there too.

 

[striker2]

you could have a leak in the exhaust manifold right before the O2 sensor. this would provide extra air to the O2 sensor giving you a false lean condition. the computer would then add extra fuel to make up the lean condition.

remove the exhaust heat shield (while the engine is cold) and inspect the manifold for any sign of a leak or a crack. even the smallest crack could cause issues. the bottom side of the manifold it harder to inspect. if you see anything that you think looks like a crack go get a manifold from a junkyard (inspect it thoroughly first) and just replace the manifold. they are generally pretty cheap from a junkyard, maybe $10-20 (if that)

 

[Paul G.]

Thanks striker2,I'll give that a good look, I have to take off heat shield to change pcv anyway.I just changed that upstream 02 sensor thursday and I tightened it pretty good, but I wasn't supposed to put some kind of thread sealant on it was I?I'll post results,Again thanks-Paul

 

[Paul G.]

update

update

Well, I'm at my wits end.I've tried everything suggested,or that I found in other posts,and I can't get rid of this p0171.No vacuum leaks found,cleaned MAF,replaced both o2 sensors,Plugs ,wires.Do these cars need a couple minutes to warm up?After first cold start if I step on the pedal it stalls or really bogs,goes away(95%)after few mins.I'm almost convinced this has something to do with my cel.I need to get an inspection sticker this week but I can't get this one code to go away.Any other suggestions would be greatly appreciated.Thanks-Paul

 

[striker2]

have you cleaned the IAC yet? it may be sticking open. this would also give you the bogging that you just described.

 

[Tony2005]

Paul G.,

A real time live data scan (about $100 at the shop or you can buy a Actron CP9180 for about $200) will help narrow down what the problem is but as you have not done it, below are some of the causes of P0171 code:

1) Air leaks after the MAF sensor or leaks in PCV system,
2) Exhaust leaks before or near O2 sensor
3) Fuel injector issue
4) Ran/running out of fuel, fuel pump not supplying enough fuel
5) Leaking EGR gasket
6) Dirty MAF sensor
7) Engine oil dipstick not seated properly

Check all these items carefully and fix what you find.

 

[Paul G.]

Ok,I think I'll go get a live data scan,also I've read about freeze frames,is this something that is included in a live scan?I really appreciate everyone taking time to help me out here but I think I've gone as far as I can go without spending big $$$$, replacing and guessing..I'll post results Thank you-Paul

 

[Tony2005]

Live scan is exactly that. You get real time engine data when the car is running.

Freeze frames are data that are "frozen" when the PCM registers the error code. That way you can read the engine data at the time the error code was recorded and determine what data is out of whack. With that you can easily (???) narrow down what the problem is which is causing the CEL code.