Bigfoot Posted March 4, 2007 Share Posted March 4, 2007 Was getting a P0171 (Lean Bank 1) here recently and finally found what it was. After my intake manifold change and valley cover change, I found I was still getting some oil in the manifold. I had seen where people had put breathers on the capped ports on the valve covers to relieve pressure and hopefully reduce oil blow-by.Well, during my thorough inspection I could hear air being pulled in through that breather. So I just recapped it and all seems to be better now. Go figure. All that air going in there was unmetered so the MAF didn't recognize it and add more fuel.And for those of you that heard me mention a rough idle problem I was having...that is now fixed as well.To top it all off, my acceleration seems to be better as well...so when we going back to the track again guys...wanna see if I can beat that 13.448 ET I had. Guess I'll get one of those oil catch cans instead. I think that will be $100 well spent. Link to comment Share on other sites More sharing options...
Buccaneer Posted March 6, 2007 Share Posted March 6, 2007 Sean, Nice job. however, just wondering why you were getting a Lean condition code if your dumping more fuel in?? it would be nice to see what is really going on with a WB connected to monitor the A/F and really see if its lean or not. Just a question and suggestion. Link to comment Share on other sites More sharing options...
Loud Pedal Posted March 6, 2007 Share Posted March 6, 2007 Sean, Nice job. however, just wondering why you were getting a Lean condition code if your dumping more fuel in?? it would be nice to see what is really going on with a WB connected to monitor the A/F and really see if its lean or not. Just a question and suggestion.I think he meant there was unmetered air that the ECM did not compensate for. Therefore the extra fuel was not added. Good find! Link to comment Share on other sites More sharing options...
Bigfoot Posted March 6, 2007 Author Share Posted March 6, 2007 David is correct ...was too much air that the MAF did not "see" therefore not enough fuel for the air going in.Main reason I posted was in case anyone else ever runs into a similar situation or intended to do same thing by puting a breather on. ;) Link to comment Share on other sites More sharing options...
Guest 1FASTC4 Posted March 6, 2007 Share Posted March 6, 2007 Tellme about oil catch cans please? I have oil leakage and misting problems from my breathers.Thanks!Steve Link to comment Share on other sites More sharing options...
Bigfoot Posted March 6, 2007 Author Share Posted March 6, 2007 I don't know about on the C4, but the C5 PCV system allows a good deal of oil to enter the intake manifold. There is a catch can made for C5's that a guy on CF sells. Click here to see what it is. Posts #69 and #73 have pics of them installed. Don't know if this helps...but...when I searched CF for that thread, I found this as well. LinkyBest of luck and let us know. All about sharing knowledge.Sean Link to comment Share on other sites More sharing options...
Jester Posted March 7, 2007 Share Posted March 7, 2007 Was getting a P0171 (Lean Bank 1) here recently and finally found what it was. After my intake manifold change and valley cover change, I found I was still getting some oil in the manifold. I had seen where people had put breathers on the capped ports on the valve covers to relieve pressure and hopefully reduce oil blow-by.Well, during my thorough inspection I could hear air being pulled in through that breather. So I just recapped it and all seems to be better now. Go figure. All that air going in there was unmetered so the MAF didn't recognize it and add more fuel.And for those of you that heard me mention a rough idle problem I was having...that is now fixed as well.To top it all off, my acceleration seems to be better as well...so when we going back to the track again guys...wanna see if I can beat that 13.448 ET I had. Guess I'll get one of those oil catch cans instead. I think that will be $100 well spent.Hi,I seem to be having the same issue, This is what has been changed on my 96 I have gone to the full cold air induction K&N Tripple Filter setup with smooth boots and a Modified MAF the Throttle body has been bored out to 58mm as has the Intake manafold. It runs crazy fast but I can smell raw fuel in the exhaust. ! Are you saying to fix this cap off the oil breather tube ? I am not getting any codes to indicate lean but I know it is cause I can smell it. Got a match!!! Link to comment Share on other sites More sharing options...
Bigfoot Posted March 7, 2007 Author Share Posted March 7, 2007 Greg, it sounds like you're running rich...not lean.With all those mods you mad need a tune to fix yours up. I'm learning a lot and fast on C5's, but I cannot say for sure on C4's. You also need to be very careful when modifying your MAF. Those things are very sensitive and easy to break.In fact, if I had to hazard a guess, yours may be reading more air than is actually flowing and therefore your PCM (? C4 ?) may be dumping more fuel than you need.Someone chime in if I'm wrong. Link to comment Share on other sites More sharing options...
Jester Posted March 9, 2007 Share Posted March 9, 2007 Greg, it sounds like you're running rich...not lean.With all those mods you mad need a tune to fix yours up. I'm learning a lot and fast on C5's, but I cannot say for sure on C4's. You also need to be very careful when modifying your MAF. Those things are very sensitive and easy to break.In fact, if I had to hazard a guess, yours may be reading more air than is actually flowing and therefore your PCM (? C4 ?) may be dumping more fuel than you need.Someone chime in if I'm wrong.The new MAF is a Granitelli ? Not sure on the spelling but it is the one for cold air induction and yes I stand corrected it is running rich not lean. I guess I could always just install spark plugs in my exhaust tips and blow some flames out the back Anyway I think I found a guy in San Diego to program a custom tune chip for me I have seen some of his work and it is the next best think to steroids for cars... Link to comment Share on other sites More sharing options...
Bigfoot Posted March 9, 2007 Author Share Posted March 9, 2007 Greg, it sounds like you're running rich...not lean.With all those mods you mad need a tune to fix yours up. I'm learning a lot and fast on C5's, but I cannot say for sure on C4's. You also need to be very careful when modifying your MAF. Those things are very sensitive and easy to break.In fact, if I had to hazard a guess, yours may be reading more air than is actually flowing and therefore your PCM (? C4 ?) may be dumping more fuel than you need.Someone chime in if I'm wrong.The new MAF is a Granitelli ? Not sure on the spelling but it is the one for cold air induction and yes I stand corrected it is running rich not lean. I guess I could always just install spark plugs in my exhaust tips and blow some flames out the back Anyway I think I found a guy in San Diego to program a custom tune chip for me I have seen some of his work and it is the next best think to steroids for cars...A computer tune is probably exactly what you need. I wonder if it's the same guy I heard about in Cali from some guys I went to for a tune for a couple weeks ago. They can do stock tuning, but if you need custom, they take the PCM out, FedEx over night to Cali, the guy updates the program and ships it back over night.They said it was good for about 50HP, but is a 3 day process. They swear by him though. Link to comment Share on other sites More sharing options...
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