OBD p0171 SYSTEM TOO LEAN BOTH BANKS

[tireman]

i keep getting fault codes on startup both banks, both banks too lean. engine searches for idle and sometimes stops completely. i disconnected the MAF and only get the MAF low code and not the others, the car does run better without the MAF connected. I removed it and cleaned with electronic cleaner, it did not appear to be dirty. Car only has 56K miles on it. I turn the check light off with my carchip and two trips later the check light comes back on with system too lean again. Anyone else have this problem? I thought it may be a vac leak, so i tightened everything up, no good there either. Anyone know who rents a smoke machine? Thanks Keith

 

[eL eS]

Do you have the V6? If so, it is your PCV tube. They tend to thermally degenerate then collapse.

 

[eL eS]

Hey BTW :W 2 :V

Please consider joining the SE Regional Group.

http://www.lincolnvscadillac.com/forumdisplay.php?f=96

We are trying to plan a gather soon and Atlanta seems like the most likely destination for the first time.

 

[tireman]

yes, i have the v6

Do you have the V6? If so, it is your PCV tube. They tend to thermally degenerate then collapse.

There are two tubes between the maf and throttle, which one is it and where does it degenerate? Thanks Keith

 

[itsnotmydaddys]

i had the same reading. all i did was unplugged the battery for a half hour and plugged it back in and it was gone

 

[Chris_n_FL]

There are two tubes between the maf and throttle, which one is it and where does it degenerate? Thanks Keith

The PCV valve and tube is underneath the fuel injector plenumn. You have to remove the intake manifold among other things to get to it.

 

[eL eS]

The PCV valve and tube is underneath the fuel injector plenumn. You have to remove the intake manifold among other things to get to it.

Yep, like Chris said but to clarify there are two intake manifolds and upper and lower which is connect to the injectors. If you do have the V6 merely disconnecting the battery is not going to resolve the problem.

There is some serious work involved but both Chris and I have been there and done that so if you decide to go it alone we can give you some remote support. All you need is some basic metric handtools such as sockets, deep sockets, and wrenches.

 

[tireman]

does the pvc pipe "T" split to both sides of the engine?

Yep, like Chris said but to clarify there are two intake manifolds and upper and lower which is connect to the injectors. If you do have the V6 merely disconnecting the battery is not going to resolve the problem.

There is some serious work involved but both Chris and I have been there and done that so if you decide to go it alone we can give you some remote support. All you need is some basic metric handtools such as sockets, deep sockets, and wrenches.

Yes i agree, disconnecting the battery won't do it. I was looking at the pvc pipe, is it the stright pipe that splits to both sides of the engine? All the hoses appear to be in excellent condition. Neither tube coming from the airflow chamber has a clamp on it. Maybe its sucking air at that point. Doing repairs is no problem for me. I used to own two BMWs which required daily repairs. This LS is a dream compared to those cars. Keith

 

[eL eS]

This piece of tube is burried deep in the engine beneath the lower intake/injector plenum.

Check these photos out:

The top is of the engine disassembled the tube is in the center of the engine turned up.

The second is a close up.

The third is what the old one looked like. It was collapsed and cracked all over.

 

[Chris_n_FL]

flashbacks!!

 

[eL eS]

flashbacks!!

I hear ya. Funny thing my neighbors have a Mazda which has a recall for the very same problem. I wonder why we can't?

 

[Chris_n_FL]

Who knows why FORD does what they do?!?

I honestly think FORD is run by a huge wheel of fortune, they just spin it to decide what they do and how they do it!!

 

[eL eS]

Who knows why FORD does what they do?!?

I honestly think FORD is run by a huge wheel of fortune, they just spin it to decide what they do and how they do it!!

Hahaha. That really made me laugh out loud!

 

[tireman]

I can't believe it!

This piece of tube is burried deep in the engine beneath the lower intake/injector plenum.

Check these photos out:

The top is of the engine disassembled the tube is in the center of the engine turned up.

The second is a close up.

The third is what the old one looked like. It was collapsed and cracked all over.

Heat is the enemy of rubber, yet they would bury the hose in such a spot and have a narrow tolerance on the sensors. Built in failure mode perhaps?

 

[eL eS]

Heat is the enemy of rubber, yet they would bury the hose in such a spot and have a narrow tolerance on the sensors. Built in failure mode perhaps?

Yeah they did not make a good design choice when it came to considering teh materials huh. In a spot like that you would think steel braided or steel belted so it would resist collapsing.

If you were to come to tampa with it i'd be happy to lend a hand.

 

[tireman]

Tampa sounds like fun!

I travel to Tampa several times a year from Atlanta to investigate auto/truck accidents. But i fly and rent a car in Tampa. Thanks for the invite!

 

[eL eS]

PM me your email address and I can shoot some stuff over that I used for my repair.

Hopefully we will have something going down up in Atlanta soon. We are going to have a live chat with the SE folks this thursday on LvC if the SE folks can make it. I have missed the past few becasue of my biznez travel.

 

[mharrison]

Well, mine is only showing the code for one bank. Think this would be the same problem?

Also is that Black Box that the PCV tube is connected to the PCV Valve?

 

[mharrison]

bump

 

[eL eS]

Well, mine is only showing the code for one bank. Think this would be the same problem?

Also is that Black Box that the PCV tube is connected to the PCV Valve?

just a vent to the crank iirc. It cannot be removed.

 

[Dirty Lincoln]

Greetings...I am new to the game here. I was surfing the net and ran across this site. This is nice. Moving on, I have this same problem. I have a 00 LS V6. I have almost got killed twice.... I checked my hoses and I have not found any bad ones yet. So I am guessing that it may be this problem. I am going to check and see if that hose is bad. I hope so because this is getting old. Any advice???Thanks.

 

[crab daddy]

This is the code that is most often thrown due to a bad front o2 sensor or a bad maf sensor. I am surprised that so many of you guys are finding the rubber tube to be the culprit.

 

[Quik LS]

not a bad O2 if both banks are reading lean at the same time (unless both go at the same time) - more likely a vacuum leak is letting air into the system after the MAF. Since the air is sneaking in after the MAF - the car does not adjust for more fuel and then runs lean.

 

[02V8Sport]

This is the code that is most often thrown due to a bad front o2 sensor or a bad maf sensor. I am surprised that so many of you guys are finding the rubber tube to be the culprit.

My 1st of 4 LS's was a 00' V6. I had the exact same problem with the PCV tube. It starts forming a leak and sucking in un-metered air to run the lean codes.

 

[crab daddy]

isnt P0171 bank1 sensor1.... not both?

also, if the maf is actually going bad (which often happens when using K&N style filters due to oil), It would show both banks lean because it isnt metering correctly.

Just saying that it is something to look into if the tube deal doesn't work (the cheap fix).