blackenedwings

So I got my car washed this morning in a hurry on the way to Easter Sunday services (ugh) and because I didn't have much time I went through one of those touchless washes at the gas station. I've gone through it a bunch of times, but I had decided to stop going through it because with my vented hood water would get into the engine bay. I've never had any drivability problems afterwards but sometimes steam would come out of the hood vents after the wash.

Almost immediately after existing the wash I made it through a yellow light and had to turn very sharply (90 degrees) in a hurry. My traction light went on and so did my first CEL ever. I didn't notice any problems with the car though, and I was almost at my destination so I continued to the church and parked. When I started the car to leave the traction light was finally off, but the CEL was still on. I was hoping it was just the gas cap.

When I got home I got my AccessPORT which for the first time ever I had accidentally left behind and checked the code. It showed as a P0103 - Mass Air Flow (MAF) Circuit High Input. I checked online and found this: http://www.obd-codes.com/p0103

Anybody else experienced this code? I'm wondering if some of the water from the touchless wash got under the hood and into the MAF sensor wiring. Is there anything I can do to check and make sure it is alright? I can verify the sensor is seeing 5-6 gs of flow at idle still, but I don't know what voltage I should be seeing. Should I just clear the code and continue about my business?

kellyrx8

try cleaning the MAF before anything...

blackenedwings

Well I inspected the car carefully and the MAF sensor is under the engine cover and appeared both completely dry and clean. The wires going to the sensor were possibly exposed to water, but its more likely that water hit the intake cone itself and something got sucked into the intake. I cleared the code and reset my ECU completely. For starters this wiped my fuel trims which greatly improved the performance of the car. I was only on my first performance tune from Jeff, so my trims were not fully tweaked. Over time I lost all the nice response of the tune and resetting the trims gave me back all the throttle response and power I had when he first gave me the tune. I've been holding back on further tuning NA since the turbo should be going in this month or next.

I drove the car gently for a drive cycle and received no further CELs and no negative driving impressions. Then later in the evening I went and flogged the **** out of it. It drove fantastic. MAF was showing 6 g/s steady at idle and 230 g/s at WOT! MAF voltage was steady at 1.2 which is the normal reading... so everything seems fine. I'll keep an eye on it for any future problems, but it seems to be a non-issue for now.

SiLVeRE8

iTrader: (8)

I experience this problem 2 days after I installed the AEM CAI. During WOT at 6k rpm the car felt like it hit a wall and the same CEL came on and the whole car drove like crap on my way to school. Later on that day I cleaned the MAF and reset the ECU. CEL never came back and the car felt normal during WOT, but problem with rough idle stayed until I cleaned the throttle body, took out one of the two screens in the intake, and reset the ECU. And now the car drives like new

I believe your problem has to do with water in the MAF because I found tiny dried water spots inside the AEM intake pipe.

blackenedwings

Yeah, that would make sense with what I experienced. I'm going to stay the hell out of the automatic car wash from now on. :D

rx8cited

No problem in rain?

blackenedwings

My guess at this point, since the MAF sensor and wire harness was covered by the engine cover is the water was sucked in through the intake cone when the car wash blasted the front of the car. It's never been a problem before, but *shrug*. The rain doesn't seem to be an issue.

Also, I'm not sure why it mattered but the CEL only came on when I made a 50 MPH 90 degree left hand turn. :P

Brettus

iTrader: (2)

My car always runs like **** after I hose down the intercooler . Water must get the filter element wet and send a fine mist into the maf . Takes a lot longer than I would have thought for it to clear itself .

Third_eye912

iTrader: (1)

i had the same codes yesterday after i had to replace the fuel line for a nitrous tap....i had to remove the throttle body just to get to the damn hose....so after installing everything back together, i started the car and the CEL came on...so i hooked it up to the computer and the same codes came up...it turned out to be the MAF sensor wasn't in all the way, so i plugged it back up, reset the code, and the CEL hasnt come up again, but i did notice that my car is idling lower than it used to....its about 800 when before it would idle at about 1000....does anybody know what the normal idle is?

blackenedwings

Stock idle is 1000, MM sets the AccessPORT tune to idle at 900. Check your MAF flow (should be stable at 6 g/s when fully warmed up) and AFRs which should be around 15.0 at idle when fully warmed. If you are getting a stumbling idle, or your MAF values are fluctuating a lot you have an issue. If everything is stable and you aren't getting stumbles I wouldn't worry about it.

rx8cited

2004 Factory Manual: Engine Specs: Idle (rpm): AT 760-860, MT 750-850 . Where did 1000 come from? My car does not idle at 1000.

blackenedwings

Hmm, I didn't know what the listed specs were, but my car idled at 1k until MM changed it. *shrug*

SiLVeRE8

iTrader: (8)

If MAF flow is fluctuating under 6 g/s during idle and idling being sort of rough, does that mean the MAF is the cause of this issue? Would anything else be causing this?

Razz1

and 230 g/s at WOT

Ha ha... there is a tuniing thread that says you can't get that high with a NA car. Ha ha! I get the samething with a MM tune ha ha.............

Zoom Zoom Jeff!

EDIT: SiLVERE8 If MAF flow is fluctuating under 6 g/s during idle and idling being sort of rough, does that mean the MAF is the cause of this issue? Would anything else be causing this?

This is a hypothetical question. It could be several things like an aftermarket AF. If you have that problem post a new thread.

SiLVeRE8

iTrader: (8)

^ Well I am most certain that its the MAF causing this issue, but I just wanted to make sure. What happen was when my 8 threw this same code, I found that the MAF flow was under 6 g/s and continuosly fluctuating between 4 and 5 g/s. During that time, the car's idle was also kind of jumpy and low.

I didn't want to create a new thread because I believe the problem was caused by the same code. Also just wondering if it would be safer to just replace the MAF.

blackenedwings

Heh, with the BHR ignition and reset trims I'm over 240 g/s now NA! The car is fast as hell.

SiLVERE8, I would not replace your MAF sensor unless you have exhausted all the other options. Try cleaning the MAF sensor with some throttle body cleaner, if you have an aftermarket intake, tighten it down and make sure you do not have any leaks. Check the MAF wire harness and make sure it is connected securely and does not have visibly damaged wires.

I assume you have an AccessPORT, what are your AFRs like at idle? Are they fluctuating wildly too?

SiLVeRE8

iTrader: (8)

My AFR at idle is fluctuating between 14.7 and 15.4. Sometimes the idle would dip and car would shake. Also my MAF flow is fluctuating between 4 and 5 g/s during idle. I have cleaned the MAF many times already, but seems like everytime after I clean the MAF the car would run like new for about a week and craps out again after that.

Also I have had the code appeared twice already... First one about 2 months ago and last one was a couple of days ago. So I am pretty certain that the MAF is the problem unless it's the AEM intake. But many people are running the same intake and have no issue.

BTW I already bought a used MAF with 10k miles from a member on this forum. I am just waiting for it to arrive to see if that will fix my problem... I will keep you guys updated. Thanks for the help!

blackenedwings

There are a couple of things possible here... do you have an oil catch can? I have the AEM intake too, and I haven't had any issues, but I have a catch can to catch any contaminants. Running NA its not as big a deal, but I do see a lot of gunk go through the hose. If that gunk builds up in the intake pipe on the MAF sensor you will experience all sorts of issues.

Hopefully the new MAF will resolve the issue, but I would consider getting a catch can anyway, as they are pretty cheap (~$100) and easy to install. Just make sure you get one with a 9MM fitting/hose.

SiLVeRE8

iTrader: (8)

Thanks for the help and advice, but I've been having the greddy catch can for over 3 months. I definitely can see a difference in the intake and the inside of the throttle body as it is a lot cleaner.

Well if the MAF is not the issue, then all I can come up with is either vacuum leak or maybe even engine low on compression. I'll just have to see in a week....

blackenedwings

Yeah, if you have a catch can already then I would double check all of your connectors for the intake just in case. A vacuum leak is possible I guess, but I don't know why cleaning the MAF would fix the issue for a while if that were the case. I guess you will find out when you replace the MAF. I wouldn't worry about bad compression because I don't think that would cause the symptoms you are describing.

SiLVeRE8

iTrader: (8)

updates since I have installed another MAF which only has 10k miles. I have been driving the car for 3 days now and I still pretty much still see the same symptoms... So in my guess the MAF is not the real issue. I believe the black mesh screen on the dry flow filter of the AEM intake is causing the idling issue because the mass airflow is still reading 4-5 g/s. But the weird thing is the airflow is reading 230-235 g/s at 8,500 rpm.

within these couple of days I will remove the black mesh screen which is on the filter to see if that makes any difference.

SiLVeRE8

iTrader: (8)

I removed the black mesh on the AEM intake and it didnt make a difference... So I have come to believe that the fluctuation between 4-5 g/s is normal when you have an AEM intake (correct me is I'm wrong)... Because I have not felt any power lost at all. Infact today I just hit 259 g/s at 8,900 rpm and it felt like a beast. So I am guessing everything is normal.

And thats for the help blackenedwings!

SebtownRx8

went through a little water yesterday and she wasn't warmed up at all like 2 min into my drive and it died on me. tried to restart it and defently flooded the picky car. Flooded it once pretty bad and i know that starting noise. so i get out and its like ankle deep water that i have to push it through about 200 feet. try to start it for like 4 min doing the deflood no go. no signs or anything about the water warning either so i was SOL. get towed home, pull the CAI off and clean the MAF and throttle body,and air compressing to blow all the water off and out. go to start it and its a bitch to start again and its still flooded but i manage to get it started let it sit for 20 min idle and data loggin so i can review everything, took for a spin and took nice and easy, on the way back WOT and POP POP backfire for sure and traction and cel popped. looked this up and this thread was nice and informing, so i just reset it and took her out again and i was showing 385g 1st WOT and the power was back. so just follow these and thats probably a sure way to make sure there is no water. they hate water i guess.

deanrx8

Ok, my CEL came on a few months ago. I took it to the Mazda Dealer, who assessed the car. They reset it, told me it was a pending code.

I got myself a OBDII Dongle after the light came on again... P0103. I followed the steps that people have suggested...all cables/connectors are good...I checked around the MAF sensor...one of the screws was threaded, so the sensor was a bit loose, which may have been letting air in...fixed that, and properly cleaned the sensor too... reset the code....all good for about 5 kilometres...then the light came on again, same code....

1) Would a dirty air filter cause a P0103..? the filter is not too bad, but don't want to spend the cash just yet on a new air filter if it's not going to address the issue.

2) Car take longer than usual to start, and runs quite bumpy on idle. MAF showing about 4.5 to 5.5g on idle...

Any ideas? Something I have missed?

deanrx8

Ok, the air filter is fine...

Does anyone know how to test the MAF sensor with a multi-meter? Had a look online, not much help out there....