P0103 code, wtf?

[MordeKyle]

My 06 fg1 lx 5speed threw a code today, i was getting on the highway so i was giving it some gas to get going. i hit second gear at 3500rpm the engine light came on and the car shuttered hard and would not accelerate. i threw it in third and once it hit 3500rpm it did the same thing. when i would down shift from 5th to fourth the rpms would go to aout 4k and the throttle did absolutly nothing, until 3500rpm the car would shutter again.

the code i pulled was P0103, which is "MAF or VAF circuit high input" basically too much air. but why would this make my engine shutter at exactly 3500rpm? was this some sort of a safety for the engine by the esu to keep the engine from melting down?

i cleared the code and it runs just fine now. i checked to make sure my filter was still on.

only power train mod is an AEM CAI. this is the CAI that replace the one that threw a different code.

[MordeKyle]

bumpadge

[07mugencivic]

?????????

[mrbill]

Just a swag.

You've had the stock CAI in there, followed by two AEM CAI. (And a puddle.)
In the swapping in and out, chance you might have damaged the MAF?

The code points to the MAF or MAF connections.

Best is follow diagnostic procedure on pp. 11-67 & 11-68 of the FSM.
Got a good scan tool?
No?

At least:

Check MAF connections.
Check MAF.
(It's bloody unlikely that you've got a bad ECM.)

-mr. bill

[MordeKyle]

well the new cai has been in for, idk like 6months or more. and i was always extremely careful with the sensor... so idk.

[mrbill]

Next time examine the freeze data before you clear the code. That way it won't still be "idk."

-mr. bill

[NIGHTHAWKSI]

it oculd just be the design of the intake.

[1stk20z3]

well i pulled the clip of the v-tec solonoid on my car out curiosity to see if the v-tec would engage, and it did the same thing. i could not go past 3500, or was it 4500 not to sure wat RPM it was. well yea i put the clip back reset the ECU and it was fine.

[NIGHTHAWKSI]

^we already know the OP's problemis with the MAF sensor though. just wondering why.

[MordeKyle]

Originally Posted by mrbill

Next time examine the freeze data before you clear the code. That way it won't still be "idk."

-mr. bill

i dont know how to get freeze data? i dont even know what it is.

[mrbill]

Then next time you get the code, bring it to someone who can troubleshoot your car.

By clearing the code you are treating a symptom but masking the problem, whatever it might be.

When a sensor is declared bad by the ECM (which it did because the code was P0103 Mass Air Flow (MAF) Sensor Circuit High Voltage) it substitutes a default for that sensor as a fail safe. In the case of the MAF, it probably also defaulted the IAT as well. This allows the engine to continue to function. In some cases, it functions with nearly no difference in performance. In other cases, you'll notice a loss in performance. You noticed.

The ECM will store "freeze data" - several engine parameters at the time the DTC is stored, *plus* 15 seconds (every .1 second) of several engine parameters prior to that - the on-board snapshot. Depending on the ECM, each DTC will have both "freeze data" and a snapshot, or each DTC wil have a "freeze data" and only the highest priority DTC will have a snapshot. (Finally, there's a running min/max of several sensors as well.)

-mr. bill