VetteSthetics Posted December 12, 2012 Share Posted December 12, 2012 Over the weekend dragging at Bondurant, I had the check engine light come on. Everything seemed fine and I made it through the day. One of the others guys had and E code reader and there was two lean codes (70 and 71) I think. I figured it was the mass air flow sensor tripping out because of the Air raid intake I just put on. SOmeone else said that on drag runs that intake plentum can cause some air seepage if not tightened properly. The car has a tune and is running great. We reset the code and it went away. I goosed it Monday and it came back. Does anyone have any ideas. Link to comment Share on other sites More sharing options...
Big Poppa Posted December 12, 2012 Share Posted December 12, 2012 Put the factory airbox back on and live a happy life... Link to comment Share on other sites More sharing options...
Two Fangs Posted December 12, 2012 Share Posted December 12, 2012 Without datalogging the car, my immediate assumption would be that the MAF needs to be recalibrated to work with the new cold air kit. Link to comment Share on other sites More sharing options...
VetteSthetics Posted December 12, 2012 Author Share Posted December 12, 2012 Put the factory airbox back on and live a happy life... LOL! SO spending your money on frivolous things won't make you happy?? Good theory.... I am not buying it! LOL Link to comment Share on other sites More sharing options...
VetteSthetics Posted December 12, 2012 Author Share Posted December 12, 2012 Without datalogging the car, my immediate assumption would be that the MAF needs to be recalibrated to work with the new cold air kit. Thats what I thought too but I was told that regurdless tune or no tune the computer would re cal the fuel curve to account for the increased air capacity. Link to comment Share on other sites More sharing options...
Two Fangs Posted December 12, 2012 Share Posted December 12, 2012 Only within set limits. If the car is trying to add or subtract fuel at an amount greater than 25% of the set point, the light will trigger. If the calibration (tune) was not close to perfect to begin with, this can happen, or if the MAF is placed in or near a bend, this can happen. The Hitachi MAF in your car is uber-sensitive, and it dies not take a lot for it to become skewed. Placement of the MAF in a different location of the airstream alone is enough to trip the light and throw a code. Link to comment Share on other sites More sharing options...
VetteSthetics Posted December 12, 2012 Author Share Posted December 12, 2012 Only within set limits. If the car is trying to add or subtract fuel at an amount greater than 25% of the set point, the light will trigger. If the calibration (tune) was not close to perfect to begin with, this can happen, or if the MAF is placed in or near a bend, this can happen. The Hitachi MAF in your car is uber-sensitive, and it dies not take a lot for it to become skewed. Placement of the MAF in a different location of the airstream alone is enough to trip the light and throw a code. So your saying I could have ran faster the ohter day S%@T! This sound reasonable. SO what now re tune? I am tempted to clear it and place the factory box back on the car to see if the problem subsides or follows the swap... Got to buy a reader! Link to comment Share on other sites More sharing options...
Two Fangs Posted December 12, 2012 Share Posted December 12, 2012 Yeah, I would just retune for the new CAI (cold air induction). One way to validate for certain it is the MAF calibration being skewed by the CAI kit is to clear the codes, put the stock box back on and go for a couple of drives under the same conditions when the light set previously. One trip won't do it, because the light sets after it sees the problem on two trips. Link to comment Share on other sites More sharing options...
VetteSthetics Posted December 12, 2012 Author Share Posted December 12, 2012 Yeah, I would just retune for the new CAI (cold air induction). One way to validate for certain it is the MAF calibration being skewed by the CAI kit is to clear the codes, put the stock box back on and go for a couple of drives under the same conditions when the light set previously. One trip won't do it, because the light sets after it sees the problem on two trips. Sounds like a plan! thanks for the knowledge! Link to comment Share on other sites More sharing options...
Cross Posted December 12, 2012 Share Posted December 12, 2012 If its coming up lean as a code then the pcm has added over 25% more fuel and cannot correct the problem. I would look into it. Logging the o2's to see if they are in need of replacement, an air leak after the maf would be my first two guesses. Your intake would not be my first thought for the cause of this issue. Another possible is an exhaust leak around the O2's that when your getting on it is sucking in outside air and causing the O2's to get a bogus reading. Either way hope this helped. I got distracted by work and did not post this until just now, seems some others have already jumped in with close to the same advice. Looks like you should have a good feel for the direction you should go. Link to comment Share on other sites More sharing options...
Big Poppa Posted December 12, 2012 Share Posted December 12, 2012 Put the factory airbox back on and live a happy life... LOL! SO spending your money on frivolous things won't make you happy?? Good theory.... I am not buying it! LOL No, I'm just saying that the actual hp gained from a cold air intake on these cars is so minimal that it flat doesn't matter. Not worth the hassle and cost of tuning the car. Frivolous spending on the car is always welcome, but I like to see results for my money and effort. Link to comment Share on other sites More sharing options...
VetteSthetics Posted December 12, 2012 Author Share Posted December 12, 2012 If its coming up lean as a code then the pcm has added over 25% more fuel and cannot correct the problem. I would look into it. Logging the o2's to see if they are in need of replacement, an air leak after the maf would be my first two guesses. Your intake would not be my first thought for the cause of this issue. Another possible is an exhaust leak around the O2's that when your getting on it is sucking in outside air and causing the O2's to get a bogus reading. Either way hope this helped. I got distracted by work and did not post this until just now, seems some others have already jumped in with close to the same advice. Looks like you should have a good feel for the direction you should go. Sounds good man, appricate it. I am probably just going to check the obvious and then have someone do the diagnostics. Thanks buddy! Link to comment Share on other sites More sharing options...
VetteSthetics Posted December 12, 2012 Author Share Posted December 12, 2012 Put the factory airbox back on and live a happy life... LOL! SO spending your money on frivolous things won't make you happy?? Good theory.... I am not buying it! LOL No, I'm just saying that the actual hp gained from a cold air intake on these cars is so minimal that it flat doesn't matter. Not worth the hassle and cost of tuning the car. Frivolous spending on the car is always welcome, but I like to see results for my money and effort. Yes agreed on both statements!! Thanks! Link to comment Share on other sites More sharing options...
F22trainer Posted December 12, 2012 Share Posted December 12, 2012 Did a HallTech swap on a C5 and had some issues getting it tightened up properly, and it was throwing same codes. After some tweaking and tightening while holding yer mouth just right, the issues went away. Link to comment Share on other sites More sharing options...
C4orce2 Posted December 12, 2012 Share Posted December 12, 2012 I don't know Mike, I may not be an expert, especially on fancy C6s, but you may want to check the color of the car; is it ORANGE? That may answer this and other issues you may face in the future. You may have to rely on Dawg's advice--good luck!! Link to comment Share on other sites More sharing options...
Cross Posted December 12, 2012 Share Posted December 12, 2012 I don't know Mike, I may not be an expert, especially on fancy C6s, but you may want to check the color of the car; is it ORANGE? That may answer this and other issues you may face in the future. You may have to rely on Dawg's advice--good luck!! Link to comment Share on other sites More sharing options...
VetteSthetics Posted December 12, 2012 Author Share Posted December 12, 2012 I don't know Mike, I may not be an expert, especially on fancy C6s, but you may want to check the color of the car; is it ORANGE? That may answer this and other issues you may face in the future. You may have to rely on Dawg's advice--good luck!! Reference my reply in the Tucson forum for response to all future orange comments! Us Orange guys need to stick together! Link to comment Share on other sites More sharing options...
VetteSthetics Posted December 12, 2012 Author Share Posted December 12, 2012 Did a HallTech swap on a C5 and had some issues getting it tightened up properly, and it was throwing same codes. After some tweaking and tightening while holding yer mouth just right, the issues went away. Yeah... I am just hoping on closer inspection I have something loose on the ducting. Thanks! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now