I got the car back from shop last week from getting a cam installed,and dyno tune, this p0103 maf code keeps coming on pretty much immediately after I start driving the car. I’ve checked all the basic stuff such as wiring connections and intake hoses to see if any were loose. Could this be something in the tune that needs to be tweaked? Thanks

 

It's most likely in the tune. I suspect this code comes up after you've made a WOT pull as the code will come up after it detects that the MAF frequency has exceeded the max expected value set in the tune. There's a setting under "Engine Diagnostics" - Airflow / Mass Airflow Sensor/ MAF Frequency Fail High (in HP Tuners) in which the highest frequency obtained in the MAF tune can't exceed this number or P0103 code will set. Fix right by changing this setting (measured in kHz) to equal or exceed the max frequency the MAF sees under WOT Or Just delete the code in the tune (the wrong way) but will work too.

 

Ok I will let them know, I would have thought that issue would have came up during the tuning hmm also it idles around 1000 rpm when I come up to a stop. Any ideas there? Thank you for the input.

 

The idle speed can be change in the tune also. I'll guess that you have an automatic and since having a cam put in that the tuner probably raised the idle to prevent the engine from stalling when coming to a stop. Just a guess but you can ask your tuner and see if it can be lowered without stalling out.

 

Well I talked to the tuner and they said the car is tuned in speed density and the maf sensor should be out of the equation. I think being this car is just street driven the maf should be in the tune, from what I’m reading here.

 

Translation: "I didn't want to be bothered with doing the job properly."

 

Ok I will get more info

 

I asked you if your car was an automatic. Is your car an automatic or stick??????
There was a reason I asked...and tuners probably know why...

 

I’d say the tuner forgot to uncheck the SES box for P0103, which will always be present in a SD tune.

In other words, that code will always be present, unchecking the SES box (service engine soon) simply tells the pcm not to turn the light on.

 

Sorry I’ve been away for moment, but the car is a six speed, and after driving it more it appears there may be another issue. I had a 0135 code yesterday for an oxygen sensor. Now today that code is gone, so maybe I have a lazy sensor

 

ok so will the car pass emissions with the code in the system, but not turning the light on? Thanks

 

Ok so we've got a "cammed" 6spd. My thoughts on why your tuner went to "speed density" were if you had an auto he may have been trying to get rid of idle and just off idle "cam surge" as when trying to navigate into a parking spot or slow driving in a parking lot. Tuning the MAF in the lower RPM range is more difficult when you've installed a cam (more radical more cam surge) because of the way it breaths down low. How much overlap your cam has between intake and exhaust timing will determine this. Reversion can occur where the air will reverse direction through the MAF give incorrect readings and as you can imagine that makes trying to tune it more difficult. I'm not saying you can't have a tune with the MAF and since you have a stick you can overcome the surge if it's a problem with the clutch obviously. If it were me (and I didn't tune my own cars) I'd ask him to tune the car with the MAF connected and ask why he went to "Speed Density"? Can't say you won't have another MAF code pop up though. It's going to depend on the tuner's ability to have it not.

As far as emissions goes IDK but I do know messing with emissions is a big "no no" and illegal. If I were "in theory" trying to pass emissions" with the P0103 code I would not only uncheck the SES box I'd also set it to "No Error Reported". I'm not sure if they'd be able to detect that It's been changed or not though and I'm not saying you should to this.

Back in Maryland we had to go through emissions every two years back in the day and I hated it but now in Florida NADA! So you could just move to Florida and problem solved!

 

ok I appreciate you taking the time to explain these things as I just assumed the car would be tuned with the maf. I have reached out to him to ask these questions I’ll see if I get a response. I did change the oxygen sensors today as well,and one of them was loose and came off by hand, so I’m sure that wasn’t helping matters. Gonna drive it and see. Thanks again for your input.

 

Your welcome and good luck.

 

yes, the maf was probably not properly failed.

i would not worry about the sd tune though and just ditcht the maf. my sd car even passes emissions. (over a billion of engines must have been made that use sd.)

 

Ok the code is stored in the onboard diagnostic and not reporting to set cel so we are all good there. The SD tune seems to be working great at this point . It must have just needed to relearn some things I suspect because the more I drove it the better it got. Car is running spectacular at this point, not just having a problem getting the 02 monitor to set.

 

It's running better now because the fuel trims have adjusted to compensate for rich/lean conditions. I suspect your tune may still be off and could be tuned better.

 

It very well could be, but I had another shop look at the tune and they said they didn’t understand it and wanted to rewrite the whole thing, so let them and they actually made it worse. Car wouldn’t even say running at one point, and had to bring it back twice. So I have the original file back in it now. If you guys know any reputable tuners in the northwest indiana area, I would like to have someone take a look at it. Thanks

 

i wonder what in a tune a tuner can have problems understanding.

 

I’m not sure they really couldn’t provide a meaningful response, so I have the original tune back in now. Friend of mine just purchased hp tuners but hasn’t really messed with it yet, so I’m wondering if we could just copy the file in the car now and post it up here for you guys to look at?