Trex87

2006 mt 107k
P0113 IAT circuit high
Maf at idle - 4.2 to 4.6
ltft at idle - 14 to 14.8
stft at idle - -2 to 1
Idles around 820 but dips to 700 often

I know this screams vacuum leak but I've used an entire bottle of carb cleaner to check all hoses and possible leaks. I've replaced all lines except the three coming from intake tube.

*****the weird part*****
My oem 107k MAF reads the numbers mentioned above WITHOUT tripping the code p0113
BUT
when I put my brand new Denso MAF it reads the same numbers WITH tripping p0113

What?

Bad maf wiring?

Obvious loss of power, fuel pressure solid at 60psi, changed coils plugs and wires few days ago no change. Been fighting this for over a year

Help?

autotechwilliam

It shows u have no vacuum leak js

Trex87

But ltft is through the roof which would indicate a leak. And it goes down as I accelerate

autotechwilliam

True however short term fuel trim is more vacuum leak long term fuel trim is more lean issues like fuel injectors or o2 sensors and maf what are ur 02 sensors reading and do u have a motus? Scan tool with keys?



iat

autotechwilliam

Also did u change wires one at a time? Is it in the correct order

Trex87

Yeah I gotta obd2 scanner that's where I'm getting these numbers. How should I test the 02? I replaced everything in the right order the ignition wires and vacuum lines.

autotechwilliam

02 readings should be in pids with the stft and live data also could be a shortage or clean the grounds around your firewall what car is it jw

Trex87

But both ones are reading the same values. Maybe denso one is just able to throw the code?

atwood_101

iTrader: (1)

Sub'd
I'm kinda having the same things. But no CEL.
Maf at idle is about 4.2-4.3 g/ps
Stft 0 +/- 2%
Ltft 11.7% - drops when under load

Runs a little rough at idle. Gonna check out what my o2 sensors are doing tomorrow.

Trex87

Atwood you've got the exactly same thing. Loss of power as well?

autotechwilliam

My rx8 is 95k 04 so I don't really have much issues only issue was starter guess they thought motor was bad so I got car dirt cheap

autotechwilliam

I'll hook up my snap on motus and tell u my pids tomorrow during work.

Trex87

Ok cool I'll compare them to mine. I'm pretty sure the idle maf should be around 5.5

autotechwilliam

The code should not effect The engine power IAT is a thermistor that varies resistance based on temperature. As the temperature increases, resistance decreases. Low temperature results in a high signal voltage. When the PCM sees a signal voltage higher than 5 volts, it sets this P0113 check engine light code. Potential Symptoms There will likely be no symptoms other than illumination of the Malfunction Indicator Lamp (MIL - Check Engine Light / Service Engine Soon). Causes A code P0113 may mean that one or more of the following has happened: Internally failed IAT sensor Faulty connection at IAT sensor Open in IAT ground circuit or signal circuit Short to voltage in IAT signal circuit or reference circuit IAT harness and/or wiring routed too close to high-voltage wiring (e.g. alternator, spark plug cables, etc.) Faulty PCM (less likely but not impossible) Possible Solutions First, if you have access to a scan tool, is there an IAT reading? If the IAT reading is logical then the problem is likely intermittent. If the reading is less than -30 degrees, unplug the connector. Install a jumper wire between the harness connector signal and ground circuits. The IAT temperature reading on the scan tool should be maxed out at the high end. For example it should be 280 degrees Farenheit or higher. If it is, the wiring is okay, and it may have been the connection. If it isn't install the jumper wire between the IAT signal circuit and the chassis ground. If now the IAT reading on the scan tool is maxed out then check for an open in the IAT ground circuit. If you get no reading at all on the scan tool, it's likely that the sensor signal is open or the 5 volt reference is missing. Check using a DVOM (digital volt ohm meter) for a 5 volt reference. If it's there, then unplug the connector at the PCM and check for continuity on the IAT signal circuit between the PCM connector and the IAT connector.

autotechwilliam

Try to jump it like it says and best thing is to get a wiring schemetic to trace your wires easier to diag

atwood_101

iTrader: (1)

Trex87,
I must've skipped over the loss of power part. I'm not having any loss of power. Just a little bit of a rough idle.

Trex87