2002 EV Check Engine-P0171 Too Lean

[troverman]

Check Engine keeps coming on now even if I clear it. The code is P0171, system too lean bank 1. What is causing the lean condition? Does it need an 02 sensor? Is there a problem with the MAF? The van is running fine (2.8L 24V).

Thanks

[Seano]

Lean is usally too much air not enough fuel....so perhaps the MAF and O2 sensors are 'off' or parhaps the problem is on the fuel side. I would suggest the latter if the reference is to one bank of cylinders on the V6.

[troverman]

I did not clear the MIL this time (it was on last night) but this morning it is off. The weather is cold, so maybe the extra fuel injected because of the lower temperature is 'tricking' the MIL into off.

[99blackmagic]

Order yourself a MAF from Europarts SD before your whole family is stuck along the side of the road with melting ice cream and you are sitting there, helpless, waiting for a tow truck while your dad takes everyone else home.

i'm just saying...it could happen.

P.S. thinking it was a fluke, i gambled and lost on the P0171 code last spring/summer and the 125 or 140 ended up costing me 400+ due to a tow.

EDIT: http://store.europarts-sd.com/...=1262

i had perfect luck with the refurb item, i think it cost me 4 bucks to repack the old and it was credited and an email was sent. i've had perfect service from europartd_SD. for what that's worth.

hope that helps your decision.



Modified by 99blackmagic at 11:09 AM 3-24-2009

[troverman]

I kind of doubt a bad MAF would strand you. Had one fail in our E320, the thing ran really poor, trying to stall out at idle, etc, but it would run. Not sure that's the problem, either. MIL is still off, no pending codes.

[99blackmagic]

i'm quite sure it did strand us.
it was towed and the only part that was replaced (on a whim, as i had researched the code prior) was the MAF.

the mechanic that i had it towed to replaced a splitting vacuum line, a larger diameter one that was surely sucking in extra air @ idle, assisting in flooding the engine. however, ultimately (as in, within 5 miles) the CEL came back on and i sat on the decision, literally for a month. decided to not drive it, and it sat. finally, i was fed up with a nice van sitting around and ordered the MAF and when it arrived, i installed it in about 15 minutes, with a flashlight, and it started up and drove perfectly. that's been MONTHS, as it was a hot summer night we had it towed.

do as you wish, just understand that the MAF on the VR6 is prone to fouling.

[troverman]

Well the van has continued to run fine. The CEL came back on, but went out on its own. You can actually run the engine w/ the MAF unplugged. It runs rough, especially at idle, but I think I could limp home this way. Is your van a '99? If so the MAF is different than mine, maybe the later model is less prone to failure?

EDIT--

I see your van is a 2001 so the MAF would be the same. Going to run it for now, since it is running well.


Modified by troverman at 7:58 AM 4-13-2009

[rensho]

Just had this popped up on the way home. It was a hot day today climbing over Santa Cruz from San Jose. Water temps got to 215F, and ambient air was ~90F. We were crawling along in stop and go with stale hot air.
Saw the code when I got home. P0171. The O2 sensor has but 10kmi on it. Not sure if the MAF has ever been replaced. ~174kmi on van.

Anyone have any luck cleaning MAFs? I hear that various cleaning fluids kill O2 sensors these days.

[troverman]

The hotter the temp, the leaner the engine will run. If this is the first time this has occurred, I would reset the MIL and see if it happens again.

I would be interested in cleaning tips for the MAF, however.

[99blackmagic]

I cleaned my MAF before replacing it and it was not worth the $4 for the bottle of cleaner. the $100 MAF from europarts was my fix for P0171.

there was a hose with a split in it, on the right side of the engine, about 5" of hard plastic vacuum line with about a 15* bend in it. my mech found that when he had the van in for alignment. heard a hissing when it was in reverse and had his secretary shift from P->R->D->R...etc and finally found it with his hand. it was sucking air. he replaced with generic hose of appropriate size-smaller than pinky.

ultimately the MAF was the culprit for the lean code, as it didn't matter if it was hooked up or not, the van would stall.

[troverman]

How can I test the MAF? I took it out last night, there was quite a bit of oil in the plastic intake tube and some in the bottom of the MAF, but none near the 'hot wires' in the top. I checked to see if the PCV was plugged but I could blow through it freely. I cleaned the oil out and put it all back. I plugged my OBDII tool in; it can graph the MAF data. As I revved the engine, the graph rose in a pretty much linear line; at idle a basically flat line appears. It appears the MAF is working fine, and as opposed to 99blackmagic the van runs fine. It doesn't try to stall. I cleared the MIL last night but I bet it will be back on today. VW wants $199 for a new genuine MAF. Amazingly, AutoZone wants $227 for a rebuilt unit. Still, I don't want to replace it for nothing. The EV is going to be used on a long trip to Canada soon (it gets better MPG than the Rover!) but it can't strand anyone. What else can cause this code?

[atletico1]

I have come to the same conslusion on my wife's New Beetle cab 2007 1.6 petrol. During the cold season - 8 months here in Norway- we never experience any CEL (and the assosiated ESP light), when temp rise above about 10 C/ 50F the CEL (lean bank 1 (code 0171) comes on and stays on (comes back after a day when cleared). I'm not too concerned about it now but it will not be possible to sell the car with those warning lights flashing. Have to do the same trick previous owner probably pulled on us- sell it during winter when it is -20C/-4 F! When the light came on first spring after we bought the car I told the garage to fix it. That ended with a $3.500 bill for changing the MAF which didn't help, then the EGR valve, then the garage took the top off sent it away to change valve steerings and grinding of the valve seats. Of course the CEL light came back but I managed to get $2000 back from the garage.