My car is running super rich! help needed
03-24-2009, 01:56 PM
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My car is running super rich! help needed Ok guys, A few weeks after I put my fenderwell cold air intake on my car, my computer has reprogrammed itself. It's sensed the colder intake temps and increased flow and it's dumping extra gas into my cylinders, I'm getting 6 mpg worse gas mileage than before and less horsepower. I've gotta get this thing tuned ASAP. My car would barely even start a few days ago because of this issue. Yesterday I unhooked the negative battery cable and let it sit for around 20 minutes, it ran much better and the mileage was back but then today when I was going to work, it was inching back down the wrong way again. Today at work I unplugged the negative cable for around 3 or 4 hours so we'll see how well this worked. i'm getting the car tuned on april 4th, do you guys think that could fix the problem? A little background, I'm running a 3" stainless pipe from the MAF down through the fenderwell with a silicone coupler then another small pipe and a K&N cone filter. I have the plastic elbow from the throttle body to MAF, MAF, and most of the piping wrapped in header wrap to insulate the pipe from the heat from the crossover header from the front bank. I have a grand prix gxp just so you know. Thanks guys.
03-24-2009, 04:25 PM
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Do you have any ideas about what it could be? after I fired it up after work it ran like complete A$$ for about 3 blocks then was fine the rest of the drive home and now it's starting to do it again, not sure what's going on. I'm gonna take it to autozone and see if it's throwin a code and not showing a light.
03-25-2009, 03:29 AM
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Would a dirty K&N cause decreased gas mileage and rough idle? The car still gets good gas mileage while I'm cruising but in the city it's a little worse, I guess it could be adjusting to the added airflow from removal of the stock airbox though 
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03-27-2009, 09:13 AM
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Ok, unplugged the negative for an hour or so, hooked it back up and let it idle for 5 or 10 minutes. it's running great now, getting 19.5 mpg city, but I still need to get it tuned because at WOT it's not performing like it should. My A/F's are all messed up. Thanks guys for helping. Glad it wasn't anything major.
03-27-2009, 09:24 AM
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did you touch your maf at all? i bent one of the wires one time it was such a small bend you could barely even tell but it ruined it and my car ran horrible and would barely even idle. if so unplug it until you get a new one your car will run just fine without it
03-27-2009, 09:56 AM
#11
Well that's really not true, though it's not the problem for this guy.
To the original poster, no one has come out and said it, so I will. Whenever you change the way that air moves through or around the MAF, it's calibration must be altered. CAI's have a heavy impact on MAF fueling.
03-27-2009, 11:48 AM
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Thanks Frost 
You can actually calibrate the reading of the MAF? Or are you talking about adjusting the A/F ratios? Sorry if it's a dumb question, I don't know that much about tuning per se. I'm only a week away from getting it tuned.
You can actually calibrate the reading of the MAF? Or are you talking about adjusting the A/F ratios? Sorry if it's a dumb question, I don't know that much about tuning per se. I'm only a week away from getting it tuned.
03-28-2009, 10:15 AM
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Well that's really not true, though it's not the problem for this guy.
To the original poster, no one has come out and said it, so I will. Whenever you change the way that air moves through or around the MAF, it's calibration must be altered. CAI's have a heavy impact on MAF fueling.
To the original poster, no one has come out and said it, so I will. Whenever you change the way that air moves through or around the MAF, it's calibration must be altered. CAI's have a heavy impact on MAF fueling.
While I'm being very sarcastic, what I'm saying is actually true lol...
03-28-2009, 11:40 AM
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It's pretty easy to prove Simply clocking the MAF like 90deg has a huge impact on fuel trimming across the board and WOT AFR. What alternative explanation can be had?
I find that removing an aftermarket lid, such as an SLP on a boltons car that was tuned (cumulative trimming to -2% to -4%) previously drives trims now to +4 to +7. Now that we replaced the less restrictive air lid with that of the OEM part, would someone really believe that the engine now needs MORE fuel, and to the order of 6-9%? We must realize then that the MAF is sampling a tiny portion of the air moving through it in order to make a very educated guess about total volume. This is the point of calibration.
Simply clocking the MAF like 90deg has a huge impact on fuel trimming across the board and WOT AFR. What alternative explanation can be had?I find that removing an aftermarket lid, such as an SLP on a boltons car that was tuned (cumulative trimming to -2% to -4%) previously drives trims now to +4 to +7. Now that we replaced the less restrictive air lid with that of the OEM part, would someone really believe that the engine now needs MORE fuel, and to the order of 6-9%? We must realize then that the MAF is sampling a tiny portion of the air moving through it in order to make a very educated guess about total volume. This is the point of calibration.
