dohc v6 Posted May 16, 2008 Report Share Posted May 16, 2008 OK, my car has been running great. I cant seem to get this code off my dash board. Its code p0171. I changed the 02 sensor, did not do anything, I checked all the vacuum lines and all was good there. My vacuum reading is around 19 at idle a little low but still ok. I checked for an exhasut leak and all was good there to. I notice that on the wideband its staying around 16.7-17.8. It will move though. Does anyone have any ideas? I am tired of having this light on and its killing my gas milage. Mark Quote Link to comment Share on other sites More sharing options...
stevegasm Posted May 16, 2008 Report Share Posted May 16, 2008 http://www.obd-codes.com/p0171 Quote Link to comment Share on other sites More sharing options...
per0781 Posted May 16, 2008 Report Share Posted May 16, 2008 try cleaning your MAF first Quote Link to comment Share on other sites More sharing options...
GPX Posted May 16, 2008 Report Share Posted May 16, 2008 My car had been running great too. Then I hastily started my project of painting my intake manifold. What was really hasty was getting up at 5:30 the next morning to put it all back together before work. It seemed to go back together alright, but now it's not idling quite right and I also got this very same code! The link above provides some good insight. I'll let you know if I have any success and what the issue was if I can determine it. Quote Link to comment Share on other sites More sharing options...
dohc v6 Posted May 16, 2008 Author Report Share Posted May 16, 2008 I disconnected the maf and it is running much better. I think it is the MAF. I will go ahead and clean it today and see if any luck with that. redcar_96- Your problem is an intake manny leak. I checked all my vacuum lines and they were all good. My vacuum is pretty straight. Quote Link to comment Share on other sites More sharing options...
BXX Posted May 17, 2008 Report Share Posted May 17, 2008 Your AFR is obviously a bit wrong. Turbo or not, you should be about stoich at idle... high 16s to low 17s is too high. The MAF like you said may be bad or undersized for you build and causing issues. Your O2 is picking it up but the ECM thinks its the O2s fault. Quote Link to comment Share on other sites More sharing options...
1990lumina Posted May 17, 2008 Report Share Posted May 17, 2008 Yeah get it down to around 14.7:1 under normal conditions. Don't wanna lean it out Quote Link to comment Share on other sites More sharing options...
19Cutlass94 Posted May 17, 2008 Report Share Posted May 17, 2008 Any AFR is the 15's is too damn high. Mid 14's and high 12's-low 13's under WOT. Quote Link to comment Share on other sites More sharing options...
dohc v6 Posted May 18, 2008 Author Report Share Posted May 18, 2008 Well I disconnected the MAF and ran the car and it was around 16-17. Good thing i did not hold it there long. I did some testing and found out its the MAF. I am on a road trio actually writing this in a pensky truck in virgina, using a blackberry as internet, pretty damn sweet. But anywyas, yeah I know I am running way to lean. The guage actually jumps around a bit from 14-16 during driving, under WOT its 10. Thanks for the help guys and I will keep ypu posted on this. Mark Quote Link to comment Share on other sites More sharing options...
PCGUY112887 Posted May 18, 2008 Report Share Posted May 18, 2008 10 under WOT? A bit too rich up top too! Quote Link to comment Share on other sites More sharing options...
dohc v6 Posted May 18, 2008 Author Report Share Posted May 18, 2008 Yeah, Shane- (RedZMonte) told me it should be around 12, so yeah I am thinking that the MAF is bad and when I go into boost its not reading the MAF right and going into LIMP mode and there for dumping fuel to make sure the car does not run to lean. Basically I have to replace the MAF and I should be good. Mark Quote Link to comment Share on other sites More sharing options...
19Cutlass94 Posted May 18, 2008 Report Share Posted May 18, 2008 LS1 MAF? Quote Link to comment Share on other sites More sharing options...
dohc v6 Posted May 19, 2008 Author Report Share Posted May 19, 2008 Yeah thats what I am using. Works great, its just bigger end caps, 3.5" instead of 3" Quote Link to comment Share on other sites More sharing options...
GPX Posted May 19, 2008 Report Share Posted May 19, 2008 redcar_96- Your problem is an intake manny leak. I went out and checked all my UIM bolts and a couple were a little less than very snug, but I don't think that's my problem. Cleaned the MAF with carb cleaner, blew out and wiped clean, re-checked all vacuum lines. The P0171 code has not returned, but car is still idling less than perfect. When cold it wants to drift up to 1500rpm at idle. Then when it's warm, it wants to drop off to 750rpm and starts pulsing. It's still responsive. It's just that the idle is not perfect like it was before I dicked around with it! Quote Link to comment Share on other sites More sharing options...
dohc v6 Posted May 23, 2008 Author Report Share Posted May 23, 2008 I replaced the MAF and the code was gone for a good couple hours driving. Anybody have any ideas of what this could be? I replced the MAF, 02, no exhaust leaks. When ever I start the car it bogs and goes crazy. It feels like a bad 02, but I replaced it and no its not a bad one. Mark Quote Link to comment Share on other sites More sharing options...
Canada Posted May 26, 2008 Report Share Posted May 26, 2008 Lean DTC...so you are getting to little fuel or to much air. You've replaced the MAF and the oxygen sensor. Take some carb clean or brake clean and spray around the intake manifold gaskets and throttle body gasket....if the engine picks up in rpm, you've got a leak. Whats your fuel pressure? You mentioned you've got a LS1 MAF.......have you reprogramed the ECM to compinsate for the larger MAF? A larger MAF with stock programing would definately cause a lean condition. Quote Link to comment Share on other sites More sharing options...
dohc v6 Posted May 26, 2008 Author Report Share Posted May 26, 2008 Its the pump, or something with fuel. I replaced all the intake gaskets. Quote Link to comment Share on other sites More sharing options...
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