Contour Enthusiasts Group Archives Forums General Troubleshooting CEL, Running Lean, What to do??

Well I installed a Pro-M, and the Aussie Pipe. I got a CEL about 24-hours later. I got the OBD-2 scan and it said I had 2 codes and 170's which said that I was running lean. So I checked all the intake hoses and made sure they were all tight, which one wasn't. That was the one that fixes the moosing. So I disconnected the battery to reset everything hoping the CEL would disappear, well it is back, and I don't know what to do. Everything seems to be rinning fine. Any Ideas would be helpful. Thanks!!

The Pro-M is probably your culprit. Lean code means that the PCM is trying to add a lot of fuel correction (more than +30% Long Term Fuel Trim + Short Term Fuel Trim). This would leave me to believe that the MAF is giving readings that are lower than they should be.

Take this example:
You are taking in 14.7 "pounds" of air and should add 1 pound of fuel. If the MAF is giving a reading of 7.3 pounds of air, the PCM will think it needs to add .5 pounds of fuel at first, but the O2 sensors will tell it that it needs to add more to be stoich. Once it adds 30%, blamo - CEL.

I bet that Pro-M is calibrated for larger injectors than you are running.

Or, you have some sort of unmetered air leak after the MAF. Same symptoms from a different problem. Or there is a bad connection at the MAF (dirty pin) sending artificially low readings to the PCM.

Would leaving it the way it is OK, or not. I know that I don't have any other leaks because I double/triple checked all of the places it could be. I will chick the pins on the meter, just to make sure, however wouldn't I get the CEL right away if that was the case?

No. A constant CEL will not display immediately. A constant CEL only displays if the "error" occurs in two out of three driving cycles. A driving cycle is basically when you start your car, go for a drive, and turn off your car.

This is probably why it didn't display until 24 hours after you installed the Pro-M and Aussie Pipe.

I have read a good amount of posts about add-ons turning on CELs.

A bigger problem is if the add-on prevents your car from passing an emissions test.

There should be lettering scratched into the meter cover. STK = stock filter. Is the K&N an open filter or in the stock housing? If the housing is stock and STK is NOT on the Pro-M then that is the problem, and vice-versa.

Tonight, I am going to put the stock MAF on and reset the computer to see if I have a vacuum leak or if it is the PRO-M. I hope that it is just a leak, however I can't see one visually or hear one. I will tell my results in 24-48hrs.

Put on stock MAF and no CEL, so I called Pro-M and mine has an E engraved which is for elbow. Since I have a KKM, it is supposed to have a C for conical filter. Also the guy said that it is supposed to have the injector size engraved, but it doesn't. I was also supposed to get sheets that show the calibration, and I didn't get those either. Pro-M told me to send it back to Muscle Motors, so they can sent it back to them. I don't see why I couldn't just bypass Muscle Motors, since it doesn't seem to be their fault. Well that's where I am at.